Stupidity on my part, unfortunately.
The issue is that when looking up the lifetime type, it's casting the currently available lifetime policy to LifetimeManager. Unfortunately, the default lifetime (TransientLifetimePolicy) isn't actually a LifetimeManager (long, not very interesting story
as to why).
I've fixed this already in the current codebase, I should be doing another source drop in the next week or two, and the fix will be in the next beta.
The workaround for now would be to explicitly register that object with the TransientLifetimeManager. The real fix was to change the default, in the file LifetimeStrategy.cs, line 83. Change:
policy = new TransientLifetimePolicy();
policy = new TransientLifetimeManager();
This was already logged as codeplex bug #6997 - I've closed it as fixed, so no need to log it again.