This is in fact exactly the same bug as #228665 for the non-bin version, which has been marked RESOLVED, and I don't have access to reopen it. (If this should have been left as a comment on the other bug, please let me know; this is a case where I don't know proper procedures.) In a nutshell, although the helper app interface works fine for me in www-client/mozilla-firefox-3.0-* (with the gnome USE flag enabled), it doesn't work in firefox-bin (which I need to be able to access Flash sites with the binary plugin, swfdec and gnash having a poor track record so far). Since a patch is already available (at https://bugzilla.mozilla.org/show_bug.cgi?id=409192, courtesy of the other bug here), a proposed solution might be to recompile the binary image with the patch and bump firefox-bin to r1.
The -bin version would never take advantage of that patch. As the bug you refer to is marked UPSTREAM (which means Mozilla is going to fix this, not Gentoo), so should this one, probably. I'll mark this bug as a duplicate of the other bug - that way the maintainers of mozilla-firefox{,-bin} will still see this bug and be able to reopen it if and when it's needed. *** This bug has been marked as a duplicate of bug 228665 ***
