Let me describe a strange scenario I had today:
User's PC abruptly loses power. I replace the PC by moving another PC (the replacement was set up but not in active use yet) to the User's desk. The User can log on to the domain fine. The user tries to print. The printer data light blinks continuously and it eventually prints out a partial page after several minutes. In the print queue on the PC it says there is an error and the job is still in the queue. I try clearing out the print queue, restarting the spooler, reinstalling the printer, resetting the printer. Nothing fixes the problem.
Meanwhile other users can print to the PC fine as long as the problematic PC doesn't have a job transmitting or stuck in the queue. I try adding two different network printers....same problem. I shut down the PC and plug it into a different network jack...