help with strange midi problem fireface 400 - ableton, m-aud

[rSphere]

i have been having some weird behavior with my setup and would appreciate any hlpe/insight from experts here.

here's what i am using: live 6, rme fireface 400, triggerfinger, m-audio radium keyboard.

the radium is going into fireface midi ch 1
the trigger finger is going into fireface midi ch 2

radium is set to send midi/track - ie., used as a regular midi keybaord for playing synths etc.
tf is set to remote input in live in order to turn on off channels, move faders etc.

the problem is: the trigger finger remote control has very intermittent behavior when the radium is on/plugged in. while it works perfectly as long the the radium is turned off or disconnected??

they are on separate midi channels via the fireface which is why I am confused by the why there should be a problem.

i have no midi out turned on in ableton's prefs.

maybe someone has an idea why this might happens or where i should dig deeper to get some answers.