I’m a big fan of Firefox and its built-in popup blocker. But in recent weeks I’ve noticed an alarming trend: an increasing number of popups and pop-unders are slipping under the Firefox radar, and appear without warning on my screen.

I’m not along in noticing this. Quite a few people have had the same problem, and they’ve emailed me, asking if I know why this is happening, and how to stop it.

The answer, unfortunately, is no — I haven’t been able to find a fix, or even understand how these annoying windows manage to appear on my screen.

So I’m asking for your help. Do you know how these popups and popunders get by the Firefox popup blocker? More important still — how can I kill them? If you know the answers, or just have ideas, post a comment and let me and the world know.

Why are popups and popunders evading the Firefox popup blocker? If you know why, and how to fix it, let me know.

I can’t count the number of times that my Mac-owning friends have told me with absolute smug certainty that the Mac is immune — absolutely immune! — to viruses and similar threats. It’s time, they would say, that I give up Windows and get a computer that has such absolute rock-solid security that it can’t be attacked.

Well, it turns out they’re dead wrong.

Symantec has just released a report that found “the Mac OS is increasingly becoming a target for…malicious activity.”

The report also notes that this is not a new phenomenon. “Contrary to popular belief,” it says, “the Macintosh operating system has not always been a safe haven from malicious code.”

The truth is, one major reason that Mac hasn’t been subject to widescale attacks is that there are relatively so few of the computers around. Estimates are that 90% of the world’s PCs run Windows, and about 5% run the Mac OS. Malware writers want to do the most possible damage, and so it makes sense to go after Windows rather than the Mac.

Gartner Inc. analyst Martin Reynolds put it succinctly when he told the Reuters news service, “The truth of the matter is that Mac is only a couple percentage points of [computer] shipments, so it’s not an interesting target.”

The Symantec report said that the Mac will become increasingly subject to attack because it will gain market share thanks to its new Mac mini, and many new Mac mini users will be less computer-savvy, and less security-aware, than existing Mac owners.

“The market penetration of Macintosh platforms will be accelerated by the much lower-priced Mac mini, which may be purchased by less security-savvy users,” the report said. “As a result, the number of vulnerabilities can be expected to increase, as will malicious activity that targets them.”

The number of Mac attacks is still minimal compared to PC attacks, and will likely remain that way forever. So Windows users will remain malware writers’ main targets. Knowing the Mac is under attack is cold comfort when your PC gets put out of commission by a nasty bit of spyware.

Still, misery loves company. So to my Mac-owning friends: Welcome to my world. And Mac lovers may also want to suggest a new marketing slogan to Steve Jobs: Finally, Viruses for the Rest of Us!

What do you think about Mac security and the Symantec report? Let me know.

There’s good news for fans of Firefox — the Mozilla Foundation announced late last week that it was halting development of the Mozilla browser suite. That foundation is the same group that oversees Firefox.

Why is this good news? Because the foundation had bit off more than it could chew. It simply didn’t have the resources to continue developing both Mozilla and Firefox. The strains were beginning to show, and Firefox was about to start suffering because of it.

The foundation was slow in plugging Firefox security holes. When it did getting around to plugging them, the installation procedure for the new version of Firefox was something that Microsoft might even have blushed at. I won’t go into the gory details, but take my word for it, in many cases it wasn’t pretty.

Now that Mozilla development is being halted, we can expect that Firefox will again get the attention it deserves. The announcement couldn’t have come at a better time, because Microsoft is hard at work in version 7 of Internet Explorer.

This is another piece of good news — I’m hoping that version 7 of IE will be a significant improvement over the aged, insecure, and creaky current version. Between the competition between IE and Firefox, I think we’ll see some real browser improvements over the next year.

Ah, browser wars…nice to have them back again.

What do you think about the Mozilla Foundation’s decision to stop Mozilla development?

Google Desktop is out of beta, and despite a few minor improvements, MSN Desktop Search still beats it hands-down.

Google Desktop’s final version adds some nice new features. It indexes and searches through sites you’ve visited in Firefox/Nestcape/Mozilla, as well as through mail in Thunderbird and Netscape email. It now tackles PDF files and music, image and video files. It can be run as a floating input box, or an input box in on your taskbar, although I’ve yet to get it to work on the taskbar. And it allows for plug-ins that extend its functionality.

But it still suffers from a fatal flaw: It treats your PC as if it were the Web, and so doesn’t let you fine-tune your searches. So, for example, you can’t search by folder, and you can’t search for email based on whether it has an attachment or not. You can’t specifically search To: and From: and other email fields. There are plenty of other similar shortcomings, and all because it refuses to recognize specific file attributes or the organization of your hard disk.

MSN Desktop Search, by contrast, was built to search with Windows in mind, and so does a far better job of searching. Want to find an email sent to you in a specific month from a specific person and that has an attachment over certain size? It’s easy to do. Want to search by file type in specific folders? You can do that, and a lot more as well.

Still, I run both MSN Desktop and Google Desktop simultaneously, and I use Google Desktop on occasion. It’s great for searching through web pages I’ve visited, for example. And I also use it to find emails I’ve deleted, because it keeps the text of those documents, something that MSN Desktop doesn’t do. But when it comes to the daily work of searching, MSN Desktop Search comes out on top.

Which do you think is better — Google Desktop or MSN Desktop Search?

Is Microsoft so hard up for traffic that it has to resort to the sleazy tactics of spyware makers? Based on one feature of the beta of Microsoft AntiSpyware, that appears to be the case.

Overall, Microsoft AntiSpyware, is a very good, solid piece of software. But it has one particularly disturbing feature — in essence, it hijacks your home page, and so is guilty of doing the very thing it’s supposed to be protecting you against. And, as you might guess, it hijacks your home page to — surprise! — MSN.com.

How does it do this? In a devilishly simple and exceedingly misleading manner. When it detects that a hijacker is trying to reset your home page, it warns you and then asks whether you want to block the hijacker. When you answer yes, Microsoft AntiSpyware promptly blocks the hijacker. But it then does a hijack of its own and resets your home page to MSN.com.

If you dig deep enough, you can defeat AntiSpyware’s home page hijacking. Choose Advanced Tools–>Browser Hijack Restore, and highlight Start Page. Click “Change restore settings to a new URL,” type in your normal home page, then click OK. From now on, when Microsoft blocks a home page hijacking, it will let you keep your own home page, and won’t do a hijacking on its own.

Microsoft AntiSpyware is still in beta, so let’s hope that Microsoft changes this behavior. Apart from this grubby little feature, it’s an excellent spyware killer — one of the best ones out there.

What do you think of Microsoft AntiSpyware? Let me know.