Printing problem

When I print out a sheet, no operators are printed. They are just blank spaces. They are visible when viewing the sheet and also when doing a print preview. It just started doing this recently (I have printed sheets that came out fine). Does anybody have any idea what the problem might be? I'm using MathCAD2001 installed on an NT4.0 station printing to an HP LaserJet 5 over an NT network.

Thanks for any help

Stuart Kinzel