Another user got this from Digital Persona.

"Thank you for contacting DigitalPersona. There will be no update releases for DigitalPersona Personal in the future. There will be no updates for Firefox 4 nor Internet Explorer 9. IF they work they work, if they do not work with DPPersonal, then you will have to decide to either keep DPPersonal and forgo Firefox 4 or IE 9, or vice versa. DigitalPersona is leaving the consumer market and is focusing on business applications. In fact, DigitalPersona Personal will not longer be supported after Mid-April of this year. We apologize for any inconvenience this might cause. Sincerely, Tech Team "

You could try this extension.
https://addons.mozilla.org/en-US/firefox/addon/fingerfox-se/

That sucks. How do I go back to my previous version of Firefox? thanks for the help!

For everyone that wants Digital Persona to work within Firefox after any update.

There is a way to fix it. Well, not really fix it, but more of a workaround.

You must modify the "install.rdf" file since it contains the max version of firefox that will work with digital persona. Here is how to do it.

1. Find the file. For most computers you could probably follow this address... but every computer is a little different, so you may have to find it using similar info.

            C:\Program Files (x86)\Mozilla Firefox\extensions\{972ce4c6-7e08-4474-a285-3208198ce6fd}

2. The "install.rdf" file with the most recent date is the one you want to change. I suggest making a copy of this file before modifying it, just in case something doesn't work. I just pasted it to the desktop.

3. Open the "install.rdf" file that is in the firefox folder, it should ask you what program you want to use to open it. Select the option that allows you to select from programs already installed on your computer. You want to open this file with notepad.

4. It may seem like just a big mess of words and numbers. Look for this part:

             "em:maxVersion>3.7.16</em:maxVersion"

</pre>
5.  As you will see, it will actually say 3.6.16.  I have already changed mine by changing the 6 to a 7.  What this does is allows Digital Persona to work until that update.  I don't suggest putting to big of a number there though, just change it to 7 and if it stops working again, you can always change it again.
6.  After you change it do 3.7.16, click file and save.  At this point, you can close notepad, if you forget to save it, it will ask you to save it.
7.  Restart firefox and it should be working again.  
I am not the one who came up with this fix.  I found somewhere it was blogged on the internet some time ago, and just today used it again and it has worked perfectly every time.  very simple to do.  Some actually give you the corrected install.rdf file to put in there, but I suggest just doing it yourself.  You never know what "extras" someone may be putting into their uploads.
Hope this helps.  I know that I don't keep my passwords, and I use this program religiously.

i brought up the Install.rdf in note pad. Ill it showed me was:

<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

    xmlns:em="http://www.mozilla.org/2004/em-rdf#">

 <Description about="urn:mozilla:install-manifest">
   {972ce4c6-7e08-4474-a285-3208198ce6fd}
   4.0.1

    
   
     <Description>
       <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}
       4.0.1
       4.0.1
     </Description>
   </em:targetApplication>

   
   Default
   The default theme.

   
   Mozilla
   Mozilla Contributors

   
   true

   classic/1.0
 </Description>      

</RDF>

Not what would i change on this? Can you help? thank you

I copied the solution from another source, it worked for me in FF 4.

We are very happy to tell you there is good news. The latest version of HP SimplePass(7.0.74.0) has already supported FireFox4 and IE9.

Please follow below these step instructions: 1. Uninstall current HP SimplePass on your computer. 2. Install HP SimplePass and try again.

Hint: The latest version of HP SimplePass is available for download at http://www.egistec.com/websitedownload/patch/bioexcess/HPSimPlePass7.0.74.0.zip

Note: Before you will uninstall HP SimplePass, you can backup the data of Online Account. How to backup the data of Online Account: a). Open the Control center. b). Select “General Settings -> Data Backup Settings” c). Click “Browse…” to select a place to put your backup file. And input backup password and Hint. d). Check “Online Account data” option. And then Click “OK”. Backup data successfully. After reinstalling HP SimplePass, you can restore the backup file. How to restore the data of Online Account: a). Open the Control center. b). Select “General Settings -> Data Restore Settings” c). Click “Browse…” to select your backup file. And input backup password. d). Click “OK”. Restore data successfully.

Please do not hesitate to contact us if you need any further assistance.

Yours Sincerely EgisTec Customer Services