Another bootcamp / windows 7 problem

I'm sorry if this is a repeat thread, I've spent a few hours googling, and searching various techie forums for someone who has had the same problem. I found similar problems, but nothing exactly like the one I am experiencing.

I installed windows 7 on a new 85gb partition on my imac 3.06ghz, 4gb, nvidia - that part was a breeze. The bootcamp drivers on my leopard installation disc were out of date, so I managed to obtain a bootcamp 2.0 driver for windows vista , which I installed. The only problem I experienced with the installation, after changing some compatibility options, was that the bootcamp tool in the control panel was there, but when opened it would bring up an error that it didn't exist. I got hold of the 2.1 update which I thought might fix this problem, it installed but I still experience the same problem

Windows 7 works beautifully apart from this. If I want to boot in osx, I need to hold down alt.

help :-s