Bradds, check your subnet mask and default gateway values for your TCP/IP properties. We had a similar situation here, and turned out that one digit was wrong on the subnet mask on the machines that were giving us trouble. For us, there was also the problem with a shared network printer that sometimes a user could print to, and sometimes he couldn't. The weird thing was, like your user, the login and print trouble was intermittent. Once we changed the subnet mask, everything was A-OK.