Delete / backspace notworking on Powerpoint 2002

[ME]

Hi
We have WinXP with Powerpoint 2002 on a Office PC here
however when using the backspace / delete keys on the
keyboard a small box appears instead.
All the usual check have been made to the PC / keyboard
etc other PC's which same config are not like this?

 

[B]

There was a very complicated answer posted a few months back (downloads and
patches, replacing files if I recall correctly), but it usually clears for a
while, if you reboot the computer (all the way to power off and restart).

B