Given the widespread printing problem you describe plus the (temporary) fix, the main suspect would be the ink cartridge. Did you by any chance try a fresh one? If that didn't make a difference but the printer prints good test pages, I wonder if the problem could be associated with the printer driver you’re using. Hence the following questions:
- Did the problem you’re having manifest itself from the first print you made or did it start later after some good printouts?
- Did you install and use a Lexmark driver that came with the printer? If so, what’s that driver’s version?
- If you’re using the driver provided by your OS, what’s its version, and that of the OS?
Finally, those little squares (missing symbols?) could also be the result of a font issue. Did printing a TIFF version as described above work for you?
