Outlook keeps crashing!!

[RPT]

I'm running XP Pro & Office XP on a 1.0 Gig computer with
512 meg RAM. I'm using Outlook for e-mail and I find that
if I try to send a message with attachments, Outlook
freezes ... the message isn't sent, the computer won't
respond & the main Outlook screen goes white. Sometimes
the message will send after repeated attempts. I notice
the same thing happens sometime when I try to open
mail ... it just freezes. It seems to be less of a probem
in OE, but my address book is attached to Outlook via my
palm, so I'd like to keep it as my default e-mail handler.

Any ideas????