Hey everyone.  Let me know if there is a more appropriate thread to post this to, but I have some solutions to some of the button script bugs people may have been experiencing.

In order for the scripts to lock in, only add one button at a time.
Exit the screen editor, check your button, restart Mach4 and check the button again.  If the button was working before restart but not after, go into the screen editor, copy the button, paste the copy, and then delete the copy.  Repeat the process, testing the button before and after restarting Mach4.  Usually it only takes round of this process.
The worst thing you can do is try to add multiple buttons during one screen editing session.  Personally I have mostly experienced these problems when dealing with scripts that write to the RegFile but sometimes other scripts behave strangely. 
Once your button works after a restart of Mach4, it seems to be good forever.

Hope that helps!