Thank you very much! I have a diagram for the BeatBuddy splitter cable as below:
[ATTACH=full]10029[/ATTACH]
The only difference between your diagram and the one I have is that the no.6 pin (on the mini-midi connector) to the no.3 pin (on the MIDI OUT connector) is missing in your diagram.
As far as I know, my selfmade connector didn`t have the pin3/pin6 (GND) connection, but I might be wrong. Was a long time gone since I solder it. Mine works perfekt between BB and Infinity (both at the same power-supply).