ocassionally calls to lua_call freeze my application

["mightymoonlord" <mightymoonlord@...>]

Hi there,
I'm currently developing a games engine using lua 4.0 & delphi 6 
(thlua wrappers). Occassionally calls to lua_call(L,1,0) never 
return - this has the effect of freezing the engine. I am trying to 
track down the cause of this error and looking for a few pointers 
please being new to lua!

I don't *think* it's a stack overflow thing as I'm using lua_gettop 
and lua_settop and checking the stack size with lua_stackspace 
ocassionally. Can anyone give me any insight into what else might be 
causing this?

Cheers
Jim