Looks like they are a few months behind with their updates.
http://support.authentec.com/KnowledgeBase/KBview/tabid/843/ArticleId/330/Browsers-supported-by-HP-SimplePass.aspx

You might want to contact their support as see what's up.
http://support.authentec.com/Forum.aspx

Thank you, that was useful. It looks like they just released an update for their TrueSuite, which is pretty the same as HP Simplepass 2011. Hopefully, an updated version of Simplepass will follow as well, after the "rebranding"... I just asked it on their forum.

I just hope this issue will not come out again in the next versions of Firefox... It looks like they are not able to keep up with the browsers update, and there isn't a "standard" way to handle this by the browsers. Well, for now, just wait...

Add-ons which are hosted at the official Mozilla Add-ons website are kept up-to-date with the new Firefox versions pretty well, but it seems that those that are hosted elsewhere don't always take advantage of the automatic update system which is built into Firefox.

In the near future (Firefox 9 or 10) Mozilla is planning to change the add-on compatibility system to always assume that an add-on is compatible with the new version of Firefox, to try to eliminate "compatibility" issues like this. Currently an add-on is considered not-compatible if the internal coding that the developer used for that add-on is lower than the new version of Firefox. Most of the time it's just a "number thing" in the add-on - like 5 vs 6 - that disables the add-on as being not-compatible, and it is up to the developer to fix that little "number thing" after testing his add-on with the new version of Firefox (usually during the 6 week Beta phase of the development cycle).

But I'm not sure how that is going to work out for users - my concern is when an extension isn't really compatible with a new version of Firefox, how is the user going to determine exactly which extension just broke Firefox or is causing problems?? Not the easiest thing to figure our if the user has many extensions installed - which one is screwing up Firefox and needs to be fixed?? I guess only time will tell how well that is going to work out for Firefox users.