MIDI problems in Cubase 6 when using external MIDI devices)

Hello.

I’m running Cubase 6 on Mac OS X Version 10.7.3 and am using a Saffire Pro40 audio/MIDI interface. I have 3 external MIDI hardware devices/instruments which I am trying to use together in Cubase. One device is my master keyboard and the other 2 are a synth and sound module connected to the master keyboard using the daisy-chain method.

Here is my problem:

If I just record one midi track on MIDI channel 1 from one of my external instruments, everything is fine. However, when I try to layer a second midi track (e.g. on MIDI channel 2) from a different external MIDI instrument, the midi notes I play on my master keyboard seem to interfering with the MIDI notes on MIDI channel 1. In other words, I think everything is being sent to MIDI channel 1 as well as the MIDI channel the second instrument is set to. This happens both when recording and also when monitoring. However, once the 2nd track has been recorded and I play back both instruments, they are fine again. I am also getting a lot of ‘stuck’ MIDI notes generally (i.e. when moving a fader in the mixer or when I stop play of a midi track) and have to either reset the MIDI in Cubase or reset the patch on the external instrument to stop the stuck note.

I have doubled-checked the MIDI cable connections and all seems to be correct and I am making sure that the MIDI channels match in Cubase and the external device, so am not sure why this is happening. I don’t get any problems like this when using VST instruments.

Please can anyone help me with this?

Thanks