Hey folks. 2 problems:
 
1) All of my NI synths have started to pan hard-left on their own. Can't figure out why it's happening. I set them to CENTER, then, when I play the track, they pan hard-left unwantedly.
 
2) My headphone out on my UA25EX is only playing in MONO now. I can't get stereo back. Tried everything, but can't seem to figure it out.
 
Thanks.

You can be accidentally in OFFSET mode on your console view?  Hitting the letter O by accident can turn in on or off you can see a + sign on above the volume slider your console view if it is on.  Not sure that this is your problem but it is one of the symptoms of OFFSET mode being ON by accident.
 
Jim

Also watch out for mousewheel. Sometimes when you spin the mouse wheel and aren't aware of the control with the focus you can alter a parameter value by accident.

Make sure the two problems aren't related. Look at the waveforms (bounce, freeze or turn on wave preview if necessary) and see if they really show a hard-panned signal. Maybe it's the UA-25 that's broken.
 
Recently when my MOTU crapped out, I resurrected an old UA-25 from the junk box in hopes of getting by with it for a while, but only one channel worked. Prosumer gear just isn't built for longevity. Good thing it isn't, else an audio interface might cost $20,000 if it was built by NASA.