After my 1st post I started thinking "What else could they be other than Mach Coords"?  D'Oh.  Well anyway, I started to suss out what happened.  It did it again so I know I'm not totally losing it.
Here's what I did and what happened...
Loade Mach3 V2.31  Set up my Work Offset, loaded the G-Code and hit Run. The first line of my code was a G1 X -.500 so, I got a message saying "Soft Limits warning continue?"  I said yes and the file halted on a Soft Limits limit.  Weird?  So I jog around a little in the Neg area.  Do a Goto Z (Work Offset) and Run the file again.  All is OK.  So for some reason the first time it/Mach sees  a Neg it sounds the Softlimits alarm (almost as if it doesn't realize that there is a work offset being used).  Then, after a little 'massage'  the ol girl comes around!  Weird but 'not a show stopper'
Sid