I've finally had time to look at this for myself. Seems Tormach worked around a Mach3 race condition bug (nasty), but in doing so, made a mistake of their own.
On the XY probe screen, there are four buttons to probe with on the left-hand side - X+, X-, Y+, Y-. While making the fix, they forgot to set the flag for being in metric on all the buttons except X+. Fixing this is not difficult, it is a one-liner per button.
Find the MachScreen directory, and fire up the executable. Use it to open the PCNC1100M3-II.set file. One by one, double-click on the buttons that need fixing, and look in the code window that appears. You should see the following at the top of the code:
Code:
Option Explicit
Rem ©2008 Tormach® LLC. All rights reserved.
' Changelog
' 5/12/2011 Changed method of aquiring probe tip diameter *dpr
Dim Posn ' current position
Dim Metric as Boolean
Dim Dist as Double ' distance we are prepared to go probing
Dim OffDist as Double
Dim ProbeRad as Double
Dim UserTool as Integer
Dim X, Y as Double
Dim Tol as Double
Dim Tripped as Boolean
If GetOEMLed (16) Then
Message "Cannot probe when displaying Machine cordinates in axis DROs"
Else
Code "G90G80G69G50"
Add the following line right under that section. If you aren't sure, look in the X+ buttons code to check what you are doing.
Code:
Metric = GetOEMLED(802)
Save the file as something other than the original name, then go to Mach3 and load the screens, and try it out. If you are happy, backup your original .set file, and rename the fixed one to the original filename.
For what it is worth, I've just downloaded the trial version of ProbeIt!, and am heading out to the shed to give it a whirl. At a minimum, I need boss probing, and the tip compensation in ProbeIt! looks very useful as well.