0.91 luabind::call_function - leak

When i call a lua function with a non primitive object (e.g. not string, int) which class i registered to luabind - everytime i call the lua func, the memory usage increases.

I have a loop, that calls the lua func 100k times - after that my usage increases by a few MB.

The lua func is empty and does nothing.

However, if call lua_gc(luaState, LUA_GCSTEP, 1); after every invoke, the usage does not increasse ( but at the end, 4KB remain no matter how many loop iterations i have  - i gather this is the metatable for the object class that remains?!).

Now when i use instead of 

luabind::call_function<void>(fn,MyObj);

directly lua :

// push function on stack
fn.push(fn.interpreter());
luabind::globals(luaState)["MyObj"] = myObj; 	
// put the obj onto the stack as func arg
lua_getglobal(fn.interpreter(), "MyObj");
// call with 1 param
lua_pcall(fn.interpreter(), 1, 0, 0);

I dont need to use lua_gc(luaState, LUA_GCSTEP, 1) to have no leak at all after each invocation. (Moreover the performance increases massively, and cuts down execution time to half)

Unrelated to call_function but to luabind in general, if i put multiple objects of the same class into the globals
luabind::globals(luaState)["MyObj1"] = myObj1; 	
luabind::globals(luaState)["MyObj2"] = myObj2;

and delete the objects (and even NULL the luabind globals) - about 4k remain everytime (tho overwritting the same identifier does not increase it) - so for some reason it seems that luabind does not reuse the class metatable and creates a new one of each object? 	

It seems once i registered an object with luabind, im unable to reduce the memory usage to the same it was before registering.

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