I've an interesting new problem with Outlook that I cannot seem to find anyone else having.

After installing the Windows 8.1 update (this may not be related) my Outlook 2003 will not allow me to accept the suggestions in the dropdown provided by the autocomplete function.

The .nk2 file seems to be in good working order and only has around 400 entries. It suggests email addresses just fine, but when trying to accept a suggestion either by clicking on the dropdown or pressing enter either nothing at all occurs or I get a return. The editor window also seems to flicker when you do this as if it is losing the focus.

Anyone have any ideas?