Some programs run just once

Hi all,

I installed Vista ultimate 64 bit and I have a weird problem with some programs. They install and run fine the first time I use them but when I reboot the PC simply don't start with no error message. This happened, for example with Unreal Tournament 2003 and with a photo editor called Studioline.
I tried to run them in administrator mode and in XP compatibility mode, I also blocked the antivirus and the firewall with no success. If I use the PC in safe mode those programs run normally (actually UT2003 starts and then complains that certain features of the 3D rendering are not available then stops).
Another game that uses the UT2003 engine (America's Army) runs fine.

My video card drivers are the latest from Nvidia.

It may be me with some silly setting of Vista, if so I apologize in advance.

Many thanks

Vista x64 Ultimate
Asus P5N32-E SLI
Intel Q6600 GO
Gainward 8600GT 1Gb
2*1Gb Kingston DDR2/800