Hi, while playing with MSM using VS2010+SP1 in a very simple test project (I'm really just trying to test how to organize states classes in files), I've tried to see if I was able to create as many state machines as I wanted, so I started to write a simple std::vector<MyStateMachine> state_machines(42); Here MyStateMachine is an empty state machine class with default front-end and back-end, with only two empty states. VC10.1 produce a warning on this line saying that there will be a stack overflow because there is a runtime recursion. I checked, it does crash (in debug at least). Is it a bug? I've not found time yet to follow the code see why that produce a recursion (??!!!), but in doubt I verified simple cases : MyStateMachine state_machine ; // no problem MyStateMachine state_machines[42]; // no problem I'll post the full code here once I get home, can't access my test project at my dayjob. I think it might be a well known problem so I ask here first. Joël Lamotte