A million thanks to the people that have reported me about Vista problems, in special to Boris. Because of that I have figured out the bug that affected all versions of Force, until version 2.0.8 and 3.0b2. I don't know exactly why but the problem occurs on machines with Office 2007 installed.
I have uploaded two new versions, the Force 2.0.9 and Force 3.0 beta 3.
Thank you all!