OK ... it is just really weird that it stores it in the tool table - but really isn't saving it. I am guessing that its one of those little nagging software bugs in the program. I have seen some other kind of flakey things happen from time to time. You know where you go into the program, change a setting, are pretty sure that you saved everything, but when you go back, nothing has changed.
I am hoping that the rewrite that Brian is doing on Mach 3, Version 4 will take care of some of these type of little problems. I know that he is doing a lot of work on offsets - primarily with regards to screen display