Gidday Chris,
I persoanally would check for any software updates for the unit.
Go through the process of reloading the current software, even if it is at the current software level.
Resetting the unit back to factory defaults
If it work great, if it doesn't then don't waste any more time on the unit, call the Small Business Support Center and ask for a RMA (Return to Manufacturer Authorization.).
http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html
If the device is not working, my first take is not to try to work around any inherant hardware issue within the unit, but I gotta assume that the device is still under a three year hardware limited warranty.
http://www.cisco.com/en/US/docs/general/warranty/3year_SmallBusiness.html
regards Dave