Go to the mythbackend of the core or md that you physically have the card installed and see if it is in capture cards? I use to have that problem in mythbuntu where my two cards would flip flop.
Its not there... but i thaught that i can configure it in the devices...
The Ubuntu OS does recofnize the card... and also in lspci...
So i assume the driver is installed....
I have a 64 bit installed... should that be a problem?
The card works fine on Windows MCE so i neglect the option of hardware issue...
Thanks for your help...