I dont know if anyone else has had problems printing wirelesly from these devices, if your printer is not air print enabled then you can't print. You can download some software from collobos which will allow you to print.
Your main computer needs to be switched on and it cost approx £16 (cheaper than a new printer)
http://www.collobos.com/ There is other software out there for macs but this is the only one i have come across for windows.
