Outlook SR-1 encounters problem upon opening

I recently got a 'gently used' iPAQ that came with
ActiveSync 3.5 and Outlook 2000 (SR-1) to install on your
PC. I've installed both. Outlook worked for a while,
but now when I open Outlook I receive a message that
says "Outlook has encountered a problem and must close."
It appears to occur when the program goes to download my
POP3 new emails. I got desparate and uninstalled &
reinstalled, but to no avail. Odd thing is I can still
use Outlook when the message appears, but not for
anything useful (like sending messages). Help?