[CentOS] firefox 18

Has anyone managed to get FF 18.0 to work on Centos 5.8?

I've been hacking at it, placing a stack of .so files (from Centos 6) into a private directory, then using LD_LIBRARY_PATH to point the system to (in a shellscript that subsequently invokes ff 18) but so far I've not managed to find the right combination. I've moved over libstdc++, all or nearly all the .so files from glib2 and glibc packages. now I"m getting:

./firefox: symbol lookup error: ./libstdc++.so.6: undefined symbol: _ZNSt7num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE2idE, version GLIBCXX_3.4

and dunno either what I've done wrong, or what other things need to be brought over.

Clues appreciated. :)