Environments, Sandboxes, and the Garbage Collector

[AJ <veivavx@...>]

I have encountered a seemingly major problem that I've been trying to
fix for about two days in a decently (for me--it's around 5,000 lines
of code plus various Lua scripts) sized project of mine.  The problem
is that nothing that in a sandboxed chunk is getting collected.  For
example, I have this example Lua script:

Title = {}

function Title:Initialize()
	self.Font = Font.Create("Content/Fonts/Font")
end

Now, I load this file (named `Title.lua' for this example) using
luaL_loadfile.  I then proceed to create a new environment for this
chunk (the environment isn't entirely sandboxed--it's just there to
stop scripts from accidentally overwriting other variables, etc--there
are still getfenv() and company), set the chunk's environment to the
newly created table.  I then make a reference to it using luaL_ref in
a global table, get it back, run it, and then put the chunk's
environment in the same position in the table (so the chunk is
discarded).

I believe discarding the chunk is fine, because the `Title' table and
its sole function, Initialize, would be stored in the environment for
that chunk.  I am not too sure, however, if the chunk must be kept
around.  I run into no problems calling Title:Initialize (and in the
actual program of mine, I have many other functions that I have no
problem with).

Now, to get rid of it, I simply call luaL_unref on the table with the
correct reference.  I figured this would remove the only reference to
the environment, and so it would be collected.  However, I presume I
am wrong because the font's `__gc' event is never called until I
explicitly call lua_close on the state at the end of the program, so
my memory usage skyrockets if I constantly reload `Title.lua' (and
other Lua scripts that follow the same premise), instead of staying
around the same.

The problem is that the table is not seemingly getting collected (or
no userdata in the table is), no matter what I try to do.  Is it
because I discard the chunk, or something else?