In my case it was an easy solution , I was using Microsoft Office 2007
The reason this issue occurred for me is that the margins in word (page setup) were setup in such a way that the page would not be able to fit onto a regular a4 letterhead so it automatically diverted to a different tray according to print auto select.
To fix this I went into Printer Preferences and went to the Paper option and told it to Print on an A4 Size paper , once I did that I was able to print without any trouble. (even if you know your page setup is correct it may be worth testing this option ,
Note: Menu's will look different depending on what type of print you have you will just need to have a browse around)