Have you tried selecting the Text tool in the status bar before editing the button text? Simply clicking on the button (whether pop up or not) will not automatically allow you to edit the text. Unfortunate and not intuitive.
"Unfortunate and not intuitive" and an extra step! :((
But thanks - At least i know how to do it now.
Rick - help yourself to a free short-short story: http://50centflash.com/free-story-the-room/ - hope you like it! :D