Thanks for responding. I originally was inquiring about using the APC40 or the Oxygen 49 and then edited my message just for the Oxygen 49 to keep things simple... I guess I forgot to change the subject line, sorry for any confusion to the readers...
Anyway, I'd already tried what you suggested and have no problem getting one single knob or fader to work. The problem is on the mixer page in Logic, trying to control more than one knob or fader. After Logic "learns" one fader, when I go to the next fader it learns that one and "forgets" the first one. It does the same thing on my Oxygen 8 also, so it gotta be something I'm not doing in Logic. I haven't been able to find a step-by-step procedure for this in the online manual or on You Tube. Am I leaving something out in the process?