printers disapper and properties will not open

[JH123]

We have been having a problem with printers disappearing from the printers folder. If the printers happen to come back after you refresh you can't view any of their properties or use the add printer wizard. This only happens for some users and it is on and off. I tried going through the registry and removing everything that has anything to do with printers. This worked for most people but there are still some having the problem. It doesn't seem to be related to any particular software. The users are all running NT 4.0 our server has recently been upgraded to Win 2000. All printers are on LPR ports and I've tried changing the drivers. Right now there are thre users who all print to the same Xerox 332ST printer who are having the problem. If they reboot and remove this printer they can print to their other printers, but as long as this printer is in the printer folder they can't print to any printers. I've run out of ideas, any help would be great.