sharepoint 2003 + office standard 2007 + IE7 = bad

Hi, we decided to upgrade our versions of office to 2007 standard, and
in order to make sure everything works, I spent the whole morning
testing the thing... I was pretty surprised to see that it doesn't
work well.

We're using web folders to access documents on sharepoint, and
everytime I would double-click on a doc, it would take forever to
open, and most times, it wouldn't even open. After many reboots, I
started to make some tests while word and windows explorer were
frozen, and then realized that IE7 would also hang.

I decided to downgrade my IE to 6, and for my surprise, apparently,
everything works smoothly.

Has anyone else noticed the same behaviour?

It'll be pretty painful, if that's the only solution, as 95% of our
users are on IE7.

Also, I installed office 2003 for the sake of testing, and the problem
DOES NOT occur on office 2003.

cheers,
Fernando