What are you trying to print? How do you normally access the Print option?

Anything. If I try to print anything from emails, websites it doesn't work. I use either the print button on the page if there is one or I use the File-Print option. I've even tried Ctrl-P. Nothing works. All other browsers work fine - IE, Chrome,safari.

I had this problem the other day and this worked for me.

As a first step, reset the selected printer in your Firefox preferences:

   Type 'about:config' in the Location Bar and press Enter. A list of preferences will appear.
   Find the preference print_printer (Note: this preference is missing in Firefox profiles where you've never used the printer.)
   Right-click (context-click) that preference and select Reset. (Some users may need to reset all the printer_ preferences for a particular printer, if resetting this one master preference doesn't solve the problem.)
   Restart Firefox and see if the problem is resolved.