I have a strange problem in printing postscript files.

If I log in as root, they print as expected, (example lpr -Pprinter
If I log in as root and su to user, they print as expected.
If I log in as user, nothing happens when I enter the command,
except a short burst of hd activity.
If I log in as user and su to root, likewise nothing happens.

This is particularly annoying as Mozilla generates its print as ps
I am using SuSE 9.0 with the "default" CUPS configuration and there is
no problem printing text or pdf files, or with OOo or Konqueror.

Thanks for any assistance

Dai Compi