I got the 'ps' blues.

Whenever I type 'ps' at the Konsole, all I get as output is:
PID TTY TIME CMD
2626 pts/1 00:00:00 bash
4679 pts/1 00:00:00 ps
This is despite the fact I am running X and three Konsoles (with SETI@home, Distributed.Net in two and ps in the third). Why am I not getting a fuller output?
Cheers,
Dan