Been enjoying it so far - even under VISTA
Cept for lately - accelerator doesn't wanna work in DiRT - can configure it in game in the control menu ie: recognises the axis, just doesn't wanna let me put the pedal to the medal
oh, can also brake an get reverse of the foot pedals (also works in other games without issue.

curious to see if anyone else has encountered this?

try playing with the 'combined accel/brake axis' settings in the G25's config panel.