That's what I do as standard and strangely I never have malware intruding through my browser...

I fully agree that any platform that's the de-facto world standard is the prime target for intrusion attempts.
After all, why target Mozilla when only 1% or so of users run it when you get 95%+ when targeting IE?
The virus writers and malware authors are doing this after all for 2 reasons which are highly related through the desire to get the highest possible number of infected machines.
Those 2 are:
1) economic incentive (mainly for spyware authors and authors of trojans that turn computers into spam robots)
2) peer recognition in the cracker and malware author community.

Of course the typical Microsoft haters are unlikely to ever admit this...