Originally Posted by NJBlackBerry
Uninstall any 4.0 handheld software you installed (use Control Panel/Add Remove softtware)
Download the latest, approved, real live version of the handheld OS for the 6750 from the site.
Install it (execute the program you downloaded)
Locate and Delete "VENDOR.XML" from your C: drive
Restart Desktop Manager with the BB connected; it should load now.
I have done that and gets me quite a ways thorough the application then crashes and says fatal error.