Firefox, Gmail and S/MIME

[uly]

Trying to get S/MIME to work on Gmail and Firefox 8:

I've gotten the Penango extension, a Comodo personal certificate, and I can sign messages with S/MIME properly. However, I cannot obtain my correspondents' certificates. I think Penango is supposed to do this automatically when I receive signed messages, but it doesn't seem to be working.

Can someone help me setup Penango properly so that it will register other people's certificates, or perhaps another alternative?

TIA

[uly]

Bump!

(No response for a week. I've read the stickies but didn't see any policy on bumping...)

[koala]

If no-one here is familiar with Penango and unable to help you, try their official support line: Contact Penango

[uly]

Thanks, I've already sent them a mail... no response, though.

In the mean time, I'm open to all alternatives for S/MIME on Firefox+Gmail.