Robin, Chris
a BIG thank you for the DC help. I think I understand what's going on but will re-read WPIA and the WIKI just to make sure. I had realised that I was trying to do two possibly contradictory things but it never occurred to me to subclass wxPanel and do everything there. Transferred the code to the "main" app and it works like a dream though I seem to have lost the mouse tracking on the status bar - I guess the EVT_MOTION event is being hijacked somewhere.
Thanks once again
Alun Griffiths