Printers Disappearing from AD

I need some/help as:
I have a Windows 2000 Server and installed several printers which have been published to AD. Every morning without fail they disappear from AD but Users are still able to print to them. Only missing from Search for printers.
I have rebuilt my Server with minimum install, SP2 applied and installed a couple of the printers, next day they disappeared again.
Many thanks
Regards
Dave