keysnstix

Hi all, Firstly, I'm a newbie to these forums, but not to MD! I'm a singer and use MD live for all my (own produced) backing tracks. I mix down all my tracks to stereo mp3 files, and until I recently was given a MZ-N510 Net-MD machine, I recorded the tracks to MD using a optical out (Audio interface on PC) to the optical in on my MDS-S41. I always have the MDS-S41 set to MONO record as I prefer to get as many tracks as possible on a disc, and my PA system isn't run in true stereo. I have just downloaded SonicStage 4.2 and I would now like to be able to transfer these mp3 stereo files to the NetMD machine as I assume it's quicker than a 'real-time' recording, but I can't work out any way to do it in mono! The software detects the NetMd player and I can transfer tracks, but only in stereo, even when I've set the netMD machine as MONO. The disc starts off with 74 minutes available - I would like to double the capacity. I hesitate to use LP2 mode, as I believe it reduces the quality - is this correct? I apologise if I have garbled my requirements, and I hope someone can help out there!