Kaspersky released Password Manager Version 5.0.0.150 today. It is compatible with Firefox 5.0.

You can upgrade here: http://www.kaspersky.com/support/kpm5?level=2

Be sure to review the Install/Uninstall instructions if you want to keep your data!

Kasperski has finally released a patch that works fine with Firefox 4, 5 and 6, as well as with Google Chrome!!!! You can download the patch at the URL Firefox patch for Kaspersky Password Manager You must follow the entire procedure as described by the Kasperski techs... I just tried it, as I had the same problem as you, and it works fine!!!!