run of SDK binaries: device is busy

I installed CUDA 3.2 RC2 and corresponding Compute SDK. When I run CUDA SDK binaries (bandwidthTest, matrixMul), I obtain messages like : cudaSafeCall() Runtime API error : all CUDA-capable devices are busy or unavailable.

But deviceQuery results looks OK. There is C2050 card installed w/driver 260.19.26 under Open SuSE 11.1.
C2050 is connected w/VGA monitor (integrated VGA controller from Supermicro X8DTI mobo isn’t used), but no X11 is used.
/dev/nvidia* devices were created.

After issuing of ./bandwidthTest, for example, VGA monitor screen content is partially destroyed and contains a continous set of colored lines.

How should I run SDK binaries correctly - or what else may be the source of “busy” state of C2050 ?

Thanks in advance !

I upgraded BIOS of Supermicro system board to last 2.0a. The problem remains.
Is there some ideas other that it’s some hardware problem ?