I also am having the same difficulty. I Downloaded and installed the trial this morning, so it is version 5.0, uncorrupted by other versions. Both ConfirmWord, and PasteWord are ignored in Firefox.
This is the feature that is most important to my organization, and its cross browser compatability is crutial to our decision to purchase the product or not.
BTW, the link for the demo is the same as the link for the download.
Thanks,
Billy