1. 32-bit/16-bit call translation:

- EBP and ESP are sometimes corrupted while running 16-bit code.

2. Messaging:

- Message flow is not correct for multiple tasks
- Dialog Boxes created by WM_CREATE handler aren't visible
- MDI does not send WM_GETMINMAX message.
- resizing of MDI child windows sometimes leaves them unrepainted

3. Controls:

- Some features are missing (like VK_SHIFT aided multiple selection in listboxes)

4. Miscellaneous:

- InitializeLoadedDLLs() can't init LZEXPAND.DLL. (cs:ip => 0:0)
- LoadCursor does not correctly handle bitmap cursors
- AllocCSToDSAlias() shouldn't alloc alias for the same segment multiple times.
- Dialogs don't support resources which are referred to as integers.

5. Where to look in source files:

- grep for FIXME in the source files.