Hi all!
I have solved the problem with my printer on my network (Laserjet p2055dn, fixed ip). The problem was, that I've assigned an IP address, that was already taken by another device, namely by a switch. As a result of the conflicting IP addresses, some jobs were printing, some weren't. Because of the conflicting IP address, the printer was showing exactly the same symptoms as many had described earlier. The problem was not evident in the beginning, because I could ping the IP address, but as a matter of fact, all the time I was pinging a different device listening on the same address. I have changed the firmware to beta, but don't know if it changed anything or not. After changing the IP address, the web-interface is working and no more freezes in the print queue.
Good luck