I updated my original post, but I wanted to reiterate here as well:
There is a new build of Mach3 3.043.062 on our website (machsupport.com) which includes a patch that fixes this issue. Install this version over your previous version, restart, and you should be back in business. As always, I recommend backing up your important Mach3 files: profile(s), license, and any custom macros or screens you may have. It's always better to err on the side of caution.
-Bryanna