Open a transcript in the Transcript editor, click "Show Info" then "Edit". If you edit the line of text at the bottom (e.g. I removed an erroneous trailing slash) and press enter, the the save button doesn't change to allow you to save the file. If you mark/unmark a checkbox you can then save and commit your changes.
Just looks like whatever processes the 'Enter' keystroke needs to set the file as 'Savable' again.