Panasonic SC-NC9 DVD H02 error - help!?

Hello, I bought a Panasonic SC-NC9 DVD Surround Sound System in December 2007 and it has been brilliant.

However it's just stopped playing DVDs.
When you put in a disc it displays: 'Reading 0 - - - -' then it gives up and displays: 'Stop', then: 'DVD HO2'.

Does anyone know what this means, or how I can fix it?

BeBe
July 2009