Password Manager Not Filling Firefox Authentication Window

[Mainframer]

With Firefox 3, if I navigate to my router or network storage to program either using the web-based utilities that come with these devices, the usual authorization window pops up asking for my user name and password, but the Password Manager will neither fill these entries nor ask to save the entries if I fill them in manually.

All other website and program entries are being filled as they should be.

The filling of authorization windows works fine using IE7.

I’m running Firefox 3.0.8, Password Manager 3.00.0250.00, Client Security 8.21.0006.00 under XP SP3.

Any suggestions are welcome.