HP 1300 randomly printing pages with tiny smiley faces and square
Try reinstalling your drivers. The computer may be confused with two different sets because of your second printer. If that doesn't work, and you have another computer available, hook the printer up to that one and install the drivers and see if the problem persists. If it does, then I really don't know what you can do, because that means the problem is in the printer's internal control and would be very hard to fix. If it doesn't persist on the second computer, then you know it's the first computer that's causing it. If nothing else works, try running a scan for viruses and spyware because they too could be interfering with your printer drivers. The computer actually does communicate with the printer even when you're not printing anything. It basically checks to make sure it's still there and waits for a response back with the printer status, etc. Some other program (whether wanted or unwanted) could be interfering.