Try the usual ideas.
1. Other browsers.
2. No add ons.
3. Know IE8's compatibility modes and views.
Keep in mind that it is possible to crash IE with scripts. And since this is on a specific site, you may be experiencing a script failure. Test this by using other browsers. Some handle scripts better.
I'm very active in an online forum (like 12hrs a day). I use Windows XP sp3 IE8. Every night it hiccups on me. My iPad is ok. I can't tell if it is the forum or my computer. If I close my browser and restart it is ok. One thing it does is it is suppose to show the time stamps like 1 minute ago, 2 hours ago, etc. But when it hiccups it shows the full date and time. They said that is a Java cache thing. But they say they don't have any thing scheduled going on when I have trouble. Could my computer be doing it? The last 3 nights were these...
1/25 10:40PM so it's looking like every 23 hours or so.
Any ideas at all?