I dont think its a problem as such....Monitors as well as graphic cards come with drivers, tvs are a little different. if the Pc is an older one it probably just has the standard 4:3 ratio monitor driver installed, so if its an upgraded monitor to a 16:9 then the driver for the actual monitor will need to be installed to the pc. Its pretty standard just like buying a new printer, card etc, you need the drivers or it doesnt work properly. Hopefully its just a monitor Driver and this dude can get on.
I had the same thing when I got mine...just needed a bit of 'driver love....'