Odd Problem Mac OS 10.3

[itz_a_dreamer@yahoo.com (~~~Cindy~~~)]

Hey guys,

   I hope that this is directed to the right group. If not please let
me know. Here's my problem. I'm helping a friend with her Mac OS 10.3
(Jaguar G5) she has wireless internet accesses. (Point to Point via a
tower on a Mtn. Near by)

   She has three computers. The G5 I just mentioned, another G5, and a
G3 laptop. The other two computers are online and working just fine.
So, I've isolated the problem to this one computer.

   She can ping both domains and their number addresses. She can ping
both incoming and outgoing mail servers as well as there number
addresses. She can send out mail but can not receive it. She also can
not view websites.

   We've already swapped cables, switched ports in the router,
recreated the location, tried adding static DNS numbers, made sure
there were no proxy settings. The firewall was already off. I had her
disable appletalk and also unshare the stuff that she isn't sharing.
So, with that out of the way i'm completely stumped. Any ideas? She's
getting an IP address of 10.0.0.XXX

    Yet she can send out mail and ping! 

- itzadreamer