[NTLUG:Discuss] OT help request

[Fred]

I know this isn't the right place to get the answer but maybe 
it is a good place to start. Maybe one of y'all can direct me 
to the proper forum for this.

I have been working with a friend, trying to help him find what
I think is a weird problem in his XP system. He has 2 basically 
identical computers, both running XP, both using dialup (not at 
the same time, of course) and with one, when he sends out a
jpeg file from either his Outlook client or as an upload to his 
Yahoo mail, the dialup connection drops. Everything goes just fine
on the other computer. The modem has been swapped out with
no effect.

I have done all I can with telephone tech support. Later on I plan to
go over there and fire up the opensuse 10.3 that he has in Virtualbox
and see what happens when a jpeg is uploaded to Yahoo from there.
I would ask him to try that but I really don't think that an old bipolar 
should be put in that position.

If that works ok, like I think it will, the question is: what could cause 
the problem and, if the answer to that one is a worm or trojan, why 
don't the popular anti- programs (Spybot, Adaware, etc) pick it up?

Thanks for any help on this.

Fred