Because I made the same changes to both, at the same time, in the same place. Obviously watever the last change I made caused the issue. That change was adding AltSoftSerial. Lo and behold, the errors thrown are related to AltSoftSerial.
@tf68, actually it is duplicating the TIMER1_COMPA_vect. It is used by AltSoftSerial for the UNO as well as the sketch. I changed to timer2, it looks like the settings are the same. I will have to setup a test to make sure.