Where did my messege text go??

Hi,
This is a bit of a wierd one, and it's only happening on one PC, so I'm
guessing that there is a configuration mess-up going on somewhere.
If I send a word doc as an email attachment, File, Send To, Mail Recipient
(As Attachment) and add some text to the email, then click the send button,
the email gets sent... BUT... it arrives without any text in the email, just
the attachment. If I check the sent items, the email is there but again with
the text deleted.
This only happens if sending attachment this way. If I go through outlook,
new messege, attach a file, then all is hunky dorey, any text I add to the
email is sent too.
The same happens if I try to send from other Office apps like excel.

Has anybody any idea why this may be happening and what I can do to resolve
it?

Thanks in advance