- EBP and ESP are sometimes corrupted while running 16-bit code. - Dialog Boxes created by WM_CREATE handler aren't visible - RegisterClass() with hbrBackground = COLOR_APPWORKSPACE+1 does not work. - MDI does not send WM_GETMINMAX message. - InitializeLoadedDLLs() can't init LZEXPAND.DLL. (cs:ip => 0:0) - LoadCursor does not correctly handle bitmap cursors