This is fun for me to offer, but I'll admit I'm a bit cranky right now.
I just upgraded the forum to phpbb3 version 3.0.3, and since then the drop down menus are acting weird in IE7. Not sure why this would be happening, but when you hover them, they stay dropped. Normally I'd love to spend hours and days trying to Google this issue, and try to fix it, but I've already been doing that all morning and wanted to pick the brains of all you smart coders.
If you can help me fix this issue, I will happily send $250 to your Paypal account.
Special note - this is only happening on the drop down menu when you're on the forum - when you're on the main site, all is good. And here's a screenshot of what is happening.