Error message in ipp backend

[Dieter.Woerz at T-Systems.com]

Hello,

I just found out, that I am getting the following error message, when printing to an HP Color Laserjet using IPP:
     network ipp "Unknown" "Internet Printing Protocol (ipp)"
I have no idea, what this could mean.
I first saw this message, when doing an strace on cups to find out, why my jobs were not processed, but I get this even, when I am just executing the ipp backend without any parameters.

What can be wrong? The printer worked a few days ago and I can connect to the ipp port on that printer using telnet.

Thanks in advance

Dieter Wörz