Debugging not stopping sessions

Hi,

I'm using POE::Wheel::Run::Win32 0.16 with POE 1.006 on ActivePerl 5.10
(1003).

My POE-based program has a main session which launchs sessions which use a
P::W::R::Win32 to run an external process.
The process are running OK, the output is returned OK, the sig_child is
fired as expected.
Also, the wheel is released and destroyed.

But the problem I have is that the session around the wheel is never
released. This is a problem because I don't want to stop my main session
before all child programs are stopped.

So I wonder what is keeping the session alive.
I've not been able to reproduce the problem with a simple test case

The ASSERT flags I tried are unusable due to the amount of data they print.
I tried to track the session refcount, but it seems to be quite low.

So here is my question: what can I use to track what is keeping the session
alive ? How can I inspect the session (even using private APIs) and the
kernel ?

Olivier.