[newbie] The Craziest Thing!!!

[ai4a]

Running Mandrake 7.0
Netscape 4.74
Using the system as a Home work Station
Have 2 users:
  userA
  userB
All was working OK until the other day. I made no changes that I
remember??
userB still works OK.
userA works OK unless I start kppp. Kppp connects OK but after that I
cannot start anything else. No xterm, no Netscape, Drakconf, NOTHING,
NADA, ZIP.
If I stop kppp, anything will start then!!! Please help. I have no idea
what to do.
Charles