I have a form with a large custom control on it.  When it loads, a
property gets set in the custom control which tells it how to paint,
using VBM_SETPROPERTY.  The lp parameter of this message gets corrupted
by the time it gets to the WinProc of the custom control, and then the
whole thing collapses.  Any ideas why this value may be getting
corrupted ?

Cheers,
Chris.