As far as i'm aware of... the on-board ICD run only with their own Compiler and IDE.

Maybe i missed something thought. If i find something i'll post it here.

MicroCode ICD worked well for me... well for the really few times i used it. Did you tried to use ENABLE DEBUG and DISABLE DEBUG 'round the code section you want to debug?

If you're using any Interrupts, the ICD may react weird indeed. Hence why i would suggest you to use ENABLE DEBUG and DISABLE DEBUG only around the code section you want to look at.

As i said, i didn't use it really often.