At least 4 people this week have asked me about windows vista support for AutoCAD 2007 & AutoCAD 2007 LT. I thought others might be having the same issue.
In case anyone else is having this problem here are some links that might help.
The following service packs provide support for AutoCAD 2007 and AutoCAD LT 2007 on the Windows Vista operating system:
AutoCAD LT 2007