Hello Anonymous.

If ALL users of Firefox have the same problem with the same site, the most likely cause is that that the site itself is badly programmed and you need to contact its owners for support.

If however, this issue doesn't span across all Firefox users, then you may be having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal?

Whenever you have a problem with Firefox, whatever it is, you should make sure it's not coming from one of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in safe mode and select Disable all add-ons. If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See this article for information about troubleshooting extensions and theme. You can troubleshoot plugins the same way.

If you want support for one of your add-ons, you'll need to contact its author.

Thanks for trying, but I have disabled all add-ons and still cannot forward attachments in FF 3.6.6. A mystery.

Please try creating a new (temporary) Firefox profile: http://support.mozilla.com/en-US/kb/Managing+profiles

This is just for diagnostic purposes. Please tell me if the new profile has the same issue.

As Morbus suggested, new profile should work.

See here for more info:

http://forums-test.mozillazine.org/viewtopic.php?f=38&t=1682025