I go back to Bitminter to test if something is up as I know it will always work. If I get no work out of a GPU it's time to take it out and reseat it and check for power issues. Nothing you've said above points to me (at least) as hardware.
Thanks!
Did it with following result:
2013.04.16 [17:24] No OpenCL-compatible GPUs detected
2013.04.16 [17:24] Lacking OpenCL support. If you want to use GPUs, please install the latest drivers from your graphics card manufacturer.
Seems it is not working...