AVR-Chat

On Dec 17, 2007 1:59 PM, Dennis Clark <dlc@frii.com> wrote:
> NEVER trust a debugger.  :)  Turn off the interrupt and see if it still
> happens.  Something else may be taking you to that address and you may be
> chasing a red herring.

Check that your int vector table isn't missing any entries, or using
RJMP when it should be using JMP, that the ISRs all end in RETI, and
handle stack properly..  You also might be getting there from a called
routine that exits with an imbalanced stack. (one more or less push,
than pop)