Have you tried completely removing the old drivers and reinstall new ones? Preferbly the drivers that came with the printer or downloaded from the Lexmark homepage?
Sometimes a reinstall of drivers doesn't completely remove the old one. Try removing the printer and then go to Control Panel > Faxes & Printers. Then go to File > Server properties and remove the drivers that are related to the Lexmark printer.
If this doesn't help please post some additional information such as OS type and describe what happens exactly when you use the printer. When does your computer go into safe mode?
