Program Zero

["Joel Jacobs" <jj-at-spyparts.com>]

Sumpin funny going on here and I'm not sure what.  When I want to set my
program zero I use the manual jog with my indicator or edge finder setup in
the quill and then use the G92 command to set the axis' to what I want.
Then I go to auto mode and run a G-code file.  If while the program is
running I hit the ABORT button the machine stops and the axis displays the
current position relative to the program zero.  So far so good.  But if I go
to MDI mode now and type in G0X0 (or Y0 or Z0) it overshoots zero by half an
inch or so and stops with the X axis displaying somthing like X -0.674.  If
I then enter G92X0, the display doesn't go to zero but something else all
together - I end up having to restart EMC before I can get my program zero
back.  Any ideas what I'm doing wrong?

Joel