printer error

I had problem useing the Laser jet 1200 and it connect on the jetdirect300x, in our company, we had some data will automaticaly print throuth the print server
and some printer some time will print out some blank paper with two line on it, PCL XL Error, Illeagle media size, some time it will print out this two line. all the printer are connet to one print server Win2000 server, it happen’s very offen, I conect HP they told me it is Driver error, but I reinstall the driver. It still the same.can any one told me how do I slove this problem. I boos ask to slove this problem.
Thank you