>Well and it is H/W designed by programmers instead of
>real EE types.  Everything is running off the PC power
>supply instead of solid power supplies.

This sounds awful like mains borne spikes are coming through the power
supply into the 5V line.

I would be tempted to run a 7805 off the 12V line to power the micro, with
some extra filtering on the input side.

My suspicion is that the power spikes are upsetting the RAM locations that
the home position data is loaded into while actually using them. It may not
be hosing the actual home positions, but hosing a pointer to their location
at a critical time.

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist