Emax

Im having some confusion/difficulty with the triggering other devices 
through the EmaxII and with the arpeggiator.

I have keyboard (as controller) > hooked up to Emax II (rack) > then 
hooked up to another MIDI sound module.  
Having all three devices set to the same MIDI channel, I can 
play/trigger the module from the keyboard like normal when I have the 
Emax MIDI set to "Thru" (instead of "Out"), and when set to "Out" I 
can use the arpeggiator to trigger the sound module (this is what I 
want to do), but I cant play the module at all with the arpeggiator 
turned off (and the Emax MIDI still set to "Out") for some reason.

I want to be able to use the arpeggiator to trigger other 
modules/things but I need it to be able to still send trigger signals 
to them whether the arpeggiator is on or off.  Seems like it should 
be able to do this.. Im not sure what the problem is, any ideas?

Thanks