Printing problem with CUPS after FC3 upgrade

[felix]

Hi,

I have a strange problem. There's a computer on the network
that are connected to a printer via Samba and another one by
JetDirect (on port 9100). The computer used to be on FC2
and could print on either printer fine. After upgrading to FC3,
however, it stopped sending jobs to the printers.

More precisely, it still sends jobs to the printers, but nothing
comes out on the other end. There are no error messages or
anything. It's just a black hole.

I am totally at a loss at this point...