CUDA not working with latest drivers?

iv noticed this only now:

using WINAVI AIO Converter,

convering 500mb MKV file (were watching all of star-trek series… again) (we started a year ago),
anyway…
with 337.80 driver converting 500mb MKV to MP4 took about 3min
with 340.43 driver converting the same ITS TAKING more then 10 Min!

please… anyone…?

You’d probably be better suited by submitting a support request to the developer of that application here: http://www.winavi.com/support.htm