F5 Key (Player select) not working

Hi,

Contacted technical support via the website, and didn't hear anything back after weeks. So, here goes again....

Details:
The F5 key does not work, to select that particular player in a party <p4> (F1-F4 and F6 work). The F5 key works fine in Windows, and any other game I've tried.

Steps:
As above.. F5 key does not select/highlight player.

Date & Time:
All times

Frequency:
Always

Platform:
PC

Home built.. AMD A8-5600K @ 3.6Ghz / 8GB DDR3 RAM

Operating System:
Windows 7 Pro ( 64 bit )

Graphics Card:
AMD Radeon HD 7560D

ISP:
Virgin Media

Type of Internet Connection:
Fibre Optic @ 55Mbps