Wcf IInstanceProvider Behaviour never calling Realease() ?

Question

Hi,

I'm implementing my own IInstanceProvider class to override the creation and realease of new service instances but the Release() method never gets called on my implemented class?

It's implemented using an IServiceBehavior to attach to the exposed endpoint. No matter how hard we hammer the service the Relaease() method nevers gets called. We have the service running a per call instanceContext mode with 50 instance max. The deconstruct of the service instance gets called but not on all created instance and this looks like the gargageCollection rather than wcf realeasing and disposing.

Any ideas why the Release() method never gets called?

Thanks in Advance,

Jon