Prompt for security certificate previously always trusted?

[jjsonp]

There is a secure site I connect to. Many months ago I clicked 'Always trust' on their certificate. Now I can no longer connect.

I know the site still works because I can connect from another machine...on that machine I get the security cert prompt, I click 'Accept', and I'm in and can transfer files.

On my own machine I've tried the following things: deleted the 'trustedcertificats.xml' file in my profile folder - no change. Deleted & re-created the site via Site Manager - no change. Uninstalled FileZilla, deleted the FileZilla profile folder, re-installed, re-created the site - no change.

I'm guessing that Windows (Server 2008) is caching the site address & 'always trust' flag in the registry somewhere?

Thanks!