I just installed a netgear print server(ps121v2) and some computers print OK but some don't. Ever since I installed it I keep getting error messages showing the ethernet cable unplugged.This flashes on for 5-10 secs than goes back off and the one computer won't log onto the net. I know it's the print server cause if you unplug the rj45 from it every thing works. Is there some setting that needs changed or is this just a crummy Print server.
THANKS for any help Vinny

Describe how everything is physically connected and the IP addressing settings each device is using. Logging onto the net should be unrelated to a print server unless you have some bizarre connection arrangement or conflicting IP addressing.

Resource:
PS121v2 Installation Guide