I have not had any trouble with Mach 3 compensating for different tool lengths until this morning.  Suddenly, after I change a tool, Mach 3 fails to turn the green LED light, informing me that the tool offset is in fact recognized.  What causes this?  My code looks normal. Now when it starts to cut with the new tool, it's not compensating for tool length.  The offset in the offset window looks fine also. I am puzzled.
tony

Need to see your g-code.

and your xml and tools3.dat.
Hood

thank you gentleman for helping. I discovered that the tool had been misnumbered, that is, T2 had some crazy H **** number. As soon as I made the correction, things went back to normal.
thanks again.
tony