Cannot type in Outlook 2002

[One too many]

Running Outlook 2002 with Microsoft Exhange and Pop3

After running outlook for about 5 mins, I suddenly find I cannot type in any
of the forms, such as Appointments and Contacts. I can paste in what I want,
and use the delete button. The dialogue boxes work ok though.

I can type emails (probably because I'm using Word as my email editor).

The preview pane also freezes, and echos what was last showing.

Any ideas as to how to fix. I've tried detect and repair, deleteing my PSTs
and OSTs and starting again but to no avail.

Thanks.