I recently purchased an M-Audio UNO Midi to USB cable to access Zen Edit and had some problems with it. I know many of you use this - but my problems went unresolved. It was extremely frustrating.
I purchased the iConnectivity Mio and it worked perfectly right out of the box. This is a plug & play unit - no drivers and certainly made for the midi challenged like myself. Cost was about the same as the UNO.
Just another option to consider.