User PPP slowing down the system

[Emil Khatib]

Hi to everybody. 
I have a problem with ppp. When I execute it as a normal user, the
machine slows down a lot. For example, I can't execute "startx", it
simply doesn't do anything. I've tried doing ps -A and it shows that
"ppp -background provider" uses a lot of CPU time, even more than
konqueror, for example.
Then I tried using PPP interactively, and then the CPU time was
reduced to normal levels, but even though I coudn't execute startx.
Everything works allright when I kill ppp.
Anybody knows a solution ?