Mach4 will help this issue when it comes out. I'm not sure if Mach3 is capable of disabling this, not that I'm aware of at lease. If the problem hasn't been addressed in Mach4 you will have the option of creating your own application for the user interface, or paying someone to program it for you - based on information that Brian has leaked to us in the yahoo forum.
Come on Mach4!
Hopefully it will be as beautiful as it sounds, and any limitations that exist in the stock user interface will be able to be addressed with custom frontend software. For now, BR549 is absolutely correct in that there are some limitations/caveats that the user MUST be aware of to operate the machine safely and without error. The way I see it, $159 is not enough for what you get! As a business user I would pay considerably more, but that would make it more difficult for the hobbyist to get into the CNC world - and AFAIK that is what Mach3 was originally intended for.