Yes. Firefox 3-- whatever the official package is at this point. It says 3.0 in the about page, but I think it's based on rc1 or rc2, as Firefox hasn't officially released yet.
It's a bit too slow for me. Are you using firefox 3?
It's bound to be a bit slow running remotely like you are. It's noticeably slower for me than running a local copy, but not to the point where I'm getting the gray screen of catatonia.
It seems like what you want to do is run your browser locally, and have mythweb serve the content to it. I don't know mythTV really at all (haven't used it), but if you don't need the ssh tunnel, it may work to just put
...into Firefox running locally. You might need to configure mythweb to serve the content to your machine though.
If you do need the ssh tunnel for encryption, is this link helpful?
I can get this setup tunneling web content from apache running on my server with almost no fuss. On the client machine, I run this in a terminal:
...and sign in to authenticate the ssh session.
ssh -L 8080:localhost:80 user@server_hostname
Then, again on the client machine, I run Firefox (locally-- not in the ssh terminal!) and point it to
...and my apache server on the remote system comes up, except it's serving the content through the encrypted tunnel. Magic!
...hope that was more helpful than confusing. It can make your head spin a bit figuring out which connection goes where and what localhost is pointing to in these different contexts...