NEWBIE: qpopper

[Sebastiaan <sebas@jon00793.speed.planet.nl>]

Hello,
I have a problem with reading mail with qpopper. Reading mail with pine
work fine. I installed this package, but when logging in on the pop3 port, 
qpopper gives some errors:

$ telnet localhost 110
+OK QPOP ....
user sebas
pass haha
-ERR System error, can't open temporary file, do you own it?
+OK Pop server at onix.dorpsnet.nl signing off.

I have changed my user protection bits to rwxrwxrwx (just to be sure) and
I own my own mailbox (i.e. sebas is owned by sebas and group is mail). The
maildirectory is set with chmod 1777.

Does anyone know how I can read mail via pop3? 

Thanks in advance,
Sebastiaan