While printing to a network shared printer, some documents printed from Windows XP machines cause an additional page to be printed with the following text
PCL XL error
Warning: IllegalMediaSource
However, when printing on Windows 7 machines, there is no such issue. What causes this and how to fix it?
Related question: PCL XL Error
The problem lies in the usage of PCL6 drivers. It is likely that Windows XP does not support the drivers perfectly and thus causes errors (Illegal Media Source means that it tries to fetch paper from a tray that doesn't exist). PCL5e has been around for longer and doesn't have such issues.
Bottom line: use PCL5e over PCL6 if you encounter problems.
It could well be drivers, however most posts I've seen suggested you shut-down your printer and cold start it up (remove AC power) This worked for me.
In the Printing Preferences (go to Control Panel, Devices and Printer, right click), select the Paper/Quality tab, and change the "Source is" to "Printer Auto Select".