Re my post above...
I unplugged the Afterglow headset and shuffled a couple of other usb devices and then rebooted the system. I had to keep my wireless dongle for the Logitech keyboard in place for the password, otherwise it didn't register the keyboard.
I don't know yet if the wireless headset itself is responsible or if it's some sort of USB port / MWO glitch on some systems.
I'll notify MWO support ( along with my support ticket number ) with this outcome as now that we have a lead thanks to you brilliant gentlemen, it can now be followed up and perhaps a fix put in place so that this problem doesn't affect others who seem to be encountering the same problem.
Big kudos to Shamous13 and Durant Carlyle

Edited by Obsidian_Knight, 11 November 2013 - 10:52 PM.