All AE Creations extensions -- Clippings (except for the special version for portable devices), Delicious Post, Panic Button and Send Tab URLs -- are now compatible with Firefox 6 beta. However, there is a minor issue with Panic Button which is noted below.
Panic Button Issue With Firefox 6 beta
If the Panic Button toolbar button is not added to any Firefox browser toolbar, and you change the toolbar button image (from Panic Button's extension preferences dialog), the toolbar button image is not updated until you add the button to a toolbar and then change the toolbar button image again. See the Bugzilla bug for more details.