Reporter: A better testcase is needed. Please provide a link. I've seen setTimeout stop working on IE due to resource issues. Perhaps Windows has a timer issue when resource load is high.
Yes, this is a known issue. I'm duping this to bug 291740, because that bug has some nice testcases, although it doesn't fit the description of this bug. However, a lot of the ui in Firefox is also timer related, so it is very likely (almost certainly) the same bug. *** This bug has been marked as a duplicate of 291740 ***