I’ve just read today that development and support of Netscape products will be discontinued from February 2008. I know this was just waiting to happen—Netscape had grown inconsequential after Mozilla—but for some reason I’m a bit sad at the news.
gtkmozembed is notorious for consistently crashing in some systems. It turns out this is a problem with how the library is built; that is, a distro bug.
As of a few hours ago, the workaround has been removed. If the actual problem is not fixed in your distribution (reportedly the development version of Ubuntu has been fixed), you can either ask the gtkmozembed package maintainer to apply the fix or ask the Exaile package maintainer to apply a workaround (note that a security problem has been identified in the old workaround).