Hi there!
I have my iMac 24" with 2,8 GhZ since 1 month and after installing Leopard (because Tiger was pre-installed), I discovered no problems. Everything worked just great!
When I installed Windows XP (Yeah, I know, Windows...but I need it for Phase2 and Auto CAD) I was amazed about the fastness, this odd OS had on my iMac.
After using WIndows XP for about 1 week, big troubles appeared:
My iMac would start up normally in OS X with it's white "Boot Screen" and it's turning wheel, than switching into the blue screen mode (normally, just before displaying the desktop). But that's all - it WON'T display the desktop, just blue screen! When I boot into Windows XP, some kind of disk checking tool will appear, checks the whole disc, reboots and the whole damn thing goes in the next round... So I can't boot into Windows and OS X.
Well, after new installing Leopard and deleting the Windows partition form my system I thought, it will work again and re-installed Windows again. And here we go - the same problems again.
At my Apple store the "technician" told me that this could be a HDD failure - so I think I have to bring back my iMac and get a new HDD...
greetings
Alex