Well as it goes, I found my problem. It seemed to me to be a possible stack issue the way it was acting. Sooooo, I took another longggggg look at the interrupt routines and much to my dismay, I found a few remnants of the OLD Tim Box style syntax. He used to use a RETURN when the interrupt was to be exited. Well I found one in each of the USART interrupt routines as an early exit I used at the time before I modified them to use the DT_INT's. So it was a stack issue after all. It only goes to show, If you are going to cut and paste, Make darn sure you look at it REAL GOOD before you use it. This is the second time in a couple of years this same thing has happened to me since I switched over to the DT_INT's but, I will never go back....