I have the very same problem, this really annoys me
This is what the log says:
2012-12-12 20:02:10: Running command: poclbm.exe cablegaai_cablegaai_1:x@eu.eclipsemc.com:8337 --device=0 --platform=0 --verbose -r1
2012-12-12 20:02:10: Listener for "Default" started
2012-12-12 20:02:11: Listener for "Default": No PyOpenCL
2012-12-12 20:02:11: Listener for "Default": Not using OpenCL
2012-12-12 20:02:11: Listener for "Default": Nothing to mine on, exiting
2012-12-12 20:08:00: Listener for "Default" shutting down