printer is just silent

[Rolf Schumacher]

I've got problems installing a HP Laserjet 4050tn.
I've got no problems to install it in cups and with the ppd from HP.
The testpage prints perfectly.
But no software can see it.
I directed /etc/printcap to /var/run/cups/printcap.
Every programm offers the 4050tn as the default for printing.
But when I click on print nothing happens.
Even the access.log, error.log and page.log do not show anything.

What would you check or do as a next step?

Rolf