Unstable MIDI

Having problems with intermittent MIDI using the MIDI Controllers Receiver patch. I am routing MIDI from Plogue Bidule to QC. Signal is intermittent and i have to close/reopen programs a lot to get it to stick at all. Bidule has been quite stable for me with MIDI, so it looks like it is QC. I'm using an apple IAC bus out to QC, with HID inside bidule with the computer keyboard. I set up a layout in Bidule, midi monitors reflect all is well, then in QC the incoming signal (using the MIDI Controllers Receiver patch) works for a bit, then goes intermittent, then remains most of the time is unreliable.