Ok, got it.
wxDialog or wxFrame member functions that are used in the event map
MUST be declared with a correct argument.
OnClose() or OnRefresh() will crash, OnClose(wxCloseEvent&) or
OnRefresh(wxCommandEvent&) are ok.
My last non-debug binary is downloadable at
www.pse-consulting.de/pgadmin3/pgadmin3.zip
Regards,
Andreas