In FileMaker 10 you could create a script, with a single step, Commit Record, then attach a Script Trigger to the field, which would run OnObjectModify, in Browse mode. That has the same effect as clicking outside the field after clicking on the checkbox.
BTW, in you current file, you only had to click outside the checkbox, outside the fields, in order to Commit the record.
This same behavior could be implemented in earlier versions. But not easily. It would require an invisible button over each checkbox choice, each passing a script parameter (either hard-coded text or a "position" number), with a script to Set Field to the one you clicked on, then Commit Record. Basically all you need is the Commit, but it would have to go thru all the rest because buttons don't know what's under them unless you tell them. PITA. Better to use FileMaker 10.
I'm in Mac mode right now, which doesn't do that "record" scrolling, but I'm fairly sure the above would work. There may be another way to do it.
Thanks, that works perfectly.
I knew i could click outside the field, but that gets pretty anoying fast.