Asterisk 1.8 Lua External Libraries

I am running Asterisk 1.8 on new server and am having problems with the pbx_lua module and external lua libraries. When I try to include an external library (require “lfs” for example) I get the following error.

ERROR[19123]: pbx_lua.c:1434 load_or_reload_lua_stuff: Error loading extensions.lua: error loading module ‘lfs’ from file ‘/usr/lib/lua/5.1/lfs.so’: /usr/lib/lua/5.1/lfs.so: undefined symbol: lua_getfield

I get the same error no matter what external library I try to load and without any external libraries the dialplan loads fine. I am running the exact same set of external libraries and extentions.lua file on a 1.6.2.0 Asterisk install with no problems. Also when I run lua code outside of Asterisk (from the command line) it is able to load and use the same external libraries as I am using inside Asterisk without any problems. Is anyone else seeing this behavior with the 1.8 version?