I have a cheap midi keyboard CME U-KEY powered by USB from my new mac Pro, and connected to the 003 from its midi out to the rack's midi in port. there are noises coming from the mac's internal speaker, so the usb connection is working OK, but within pro tools, whilst it mostly recognises there is a midi signal coming in, i cannot get any sound out of pro tools, and cannot load any 'patches'. i can record (it shows the notes recorded!) but cannot play it back at all, or monitor it, i swear i have done everything in the getting started guide! Please help! Do i need a midi cable at all, ie could i just use the USB? Note that recording guitar via a microphone and playback is absolutely fine, so no core system problems. I have re-plugged in all the leads; tried all combinations of ins / outs in the mix window; tried both midi and instrument tracks to record and playback; reconfigured the midi 'studio' settings on the mac to all different combinations (note that my midi keyboard is seen as an interface as well as a new instrument by the mac). I am completely stuck! any help would be greatly appreciated.