I've been watching it for a long time, and I haven't seen it go back to an old score/stat/etc. Have you tried adding yahoo to your compatibility mode list? If anything is wrong, I'd wager it is a Yahoo coding problem - choking on IE8. Compatibility mode will allow older websites to display and act correctly in IE8.
I thought about that, but firefox is handling it fine.
I am sure cookies and tempfiles will help, but I can't be doing this everytime.
(Please just let it sit there, after a few live updates it will screw up - remember that you need to look at a game that is active and changing)
I don't think you understand what compatibilty mode is. It is part of IE8, which allows you to force a website to function as if you were using IE7. For instance, I visit a forum that uses vBulletin - the animated menu system crawls unless I use compatibilty view. Once enabled, the page renders perfectly. Try it. It's under the "Page" menu. You can also google for IE8 compatibility view.
(Oh - I did let it sit there. In fact, it's still sitting there, and it hasn't screwed up for me yet.)