CM2320 always takes from Tray 1 (if loaded)

Hi There,

I've a CM2320nf MFP.  I've an extra tray added (Tray 3).

My problem is this, if there's no paper in Tray 1, trays 2 & 3 print fine.

If there IS paper in Tray 1, then anything sent to Tray 3 prints from Tray 1.

I'f tried with the Manual feed ON & OFF in settings.

I've upgraded the firmware the newest available  (20130920)

Any assistance would be greatly appreciated.  What we want is to have paper sitting in Tray 1, but to be able to treat it as an "ordinary" tray.  i.e. that we could choose from within software whether to print to Trays 1, 2 or 3.

Thanks in advance,

Enda.