OK, so I have a weird problem.

I'm making a mill part that I have made thousands of. (VF2SS)
I use 3 work offsets on it, G54, 55, and 56.
Different features have different Datums, and G56 is simply used to center some engraving on the part.

I set the job up today, and when I run the first part, I always start with all three offsets the same in X, Y, and Z.
So, I run it, and none of the G56 engravings are cut!

I try again, and see that it is cutting air.
Z is off by .750 -1"
WTF?

I check the offsets, they all match.
Re probe the engraving tools.
Try again.
No love, still off.

So I re calibrate everything, tool probe and work probe.
Probe the tools, and the part, try again.
Still no good.
Cutting air.

So, I figure what the hell, and change the offset from G56 to G54 and give it a go.
Cuts fine!

Some how, some way, when it calls up G56, it is adding a number to the Z offset for G56.
But only G56.

Anybody have any ideas?