Internet Problems

I am running Windows XP Internet Explorer 6. and everytime i try to access certain web pages that i could get to before, it comes up with the whole. Internet has experienced a problem and needs to shutdown, Send or dont Send Error report.

How can i fix this? I tried to download Internet Explorer Service pack but it says that i have the newest version out.

Does it happen on specific sites or is it random ? Spy/Ad-ware scan lately ?

Anyways, I recommend firefox as an Internet Explorer alternative.
http://www.mozilla.com