[Zope-dev] Product manage_traceback caching old old data?

I've got a product I'm developing, but I'm finding that interactive debugging of it is being foiled by Zope's Product interface's manage_traceback method. It's caching the very first error that occured - and after I shutdown zope and restart it (having fixed the error) it still gives the same traceback. It's possible that the problem is simply the "Products" listing is at fault - it's still showing the product as "broken", even though else where in Zope I can now add products fine. Any ideas? This is with Zope 1.10.2, under ZServer.