Ok try an older version, I have found a few problems with 066 and Turn, different things from what you are talking about but they may also be due to the version and your plugin. I have informed Brian but I wont be holding my breath for a fix, if it had been in the Mill side then it likely would have been fixed right away
One of the things I have found is wear offsets get doubled for X if you are in Dia mode, another is sometimes DROs wont accept entry from keyboards.
Here is a link to 057, a version which seems to work well for me, you will have to copy\paste the link as the forum puts a http:// in front of the link automatically, so just copy the text and paste into your browser address bar then delete the http:// and then it should work, may take a few mins to start as the ftp site needs to sign you in.
ftp://machsupport.com/Mach/Mach3Version3.043.057.exeHood