thanks Mario. my phones have a double ended lead - normal size jack and a mini jack. to change you plug the other end into the phones. sounds odd but to use the mini jack you plug the normal sized jack into the phones and then the mini jack into the front panel of the pc. to use the normal jack with the uphoria i plug the mini jack into a socket on the other side of the phones and then the full size jack into the interface.

i still can't work out why BIAB played fine through phones and then without moving the plug, RB went to left channel only.