Mark, by any chance are you activating the System Protect option on the group? That would give you the problem you describe. Usually you can reactivate a group with a key combination, but System Protect would prevent anyone from making any changes to it, ever. As you describe it, the only way to fix it would be to re-upload
There is a key combo (I think it's func + group number - and if it's a 2 digit group number, func + ./no + group number -check the Easier to Read manual) to lock out a group.... best regards...Mike