"Save In" dialog (dialogue) issue
 

After opening Excel 2007 for the first time during the day, if i try to save
a workbook, i goto File - Save As, and the Save-As Dialog appears. When I
browse to where i want to save the file, i click the "Save In" Dropdown box
at the top of the dialog box and (after waiting a few seconds), I get the
list of drives to choose. however, i can't click any of them. I need to hit
Escape, and reopen the Save-as dialog box.

This is annoying! Any ideas!?

I'm running Windows Server 2003 SP2 / Office 2007 SP1