a problem about linux-firefox

[bin wan]

I used firefox based on FreeBSD perviously. but it wasn't able to run plugin
of flash player. because flash player has only Linux version. so I installed
linux-firefox by ports. Install is no error. However when the linux-firefox
actually run , I get
wan# linux-firefox
/usr/local/lib/linux-firefox/firefox-bin: error while loading shared
libraries: /usr/lib/libgtk-x11-2.0.so.0: ELF file OS ABI invalid

Linux compatibility enviroment is seem to available. see the following
wan# /compat/linux/bin/uname
Linux

And I also brand firefox-bin with Linux . see the following
wan# brandelf /usr/local/lib/linux-firefox/firefox-bin
File '/usr/local/lib/linux-firefox/firefox-bin' is of brand 'Linux' (3).

I'm not sure linux compatibility enviroment is right, because when I use ldd
,I get
wan# ldd /compat/linux/usr/bin/iconv
/compat/linux/usr/bin/iconv:
        libc.so.6 => /lib/obsolete/linuxthreads/libc.so.6 (0x28072000)
        /lib/ld-linux.so.2 (0x28054000)

According I known, Linux program need the shared library in the
/compat/linux path. so I'm puzzling.

Anyone have any suggestions as to the cause of this problem or its solution.