Renaming and Exporting Problems - Related?

I have two issues/problems that are probably self-induced, but not knowing how I induced them, I don't have a clue how to solve them. I suspect that fumblind around on the keyboard I set an option with an incorrect keyboard shortcut.

The problems are:

1. Cannot export some session stereo clips to interleaved stereo mp3 files
2. Renaming original clip splits file/clip into ".A1.L (Track A)" and ".A1.L (Track B)"

I suspect that the problems are related, but I am not sure. I need to both correct the problems and avoid them in the future.

PT 10.3.9 and 11.2
HP Z600
2 4-core CPUs
24GB RAM
5TB disc storage (3.76TB free)
High performance ASUS graphics and sound cards
Windows 7 Professional

Thanks,

Bob