I have an issue with Firefox (3.6) and IE (8) on my laptop. Both choke on some web sites. They start rendering some elements of the web page and then revert to render a blank screen. Subsequently, Firefox gets stuck and IE simply keeps trying to load the page but shows nothing. This issue has nothing to do with Flash apparently because on some sites that have it the browsers behave OK.
Upgrading Firefox from 3.6 to 5 didn't help. A virus scan (with AVG free edition) shows no infections. OS is Windows Vista with no service pack.
Any ideas on what I can do?