ENTERING_MANAGED_PKG logging level

I can confirm that this indeed happens inside namespaced packaging orgs (= the developer org of a managed package).

I have the same problem with two of our managed ISV packages. Even setting the Debug Logging Level to ERROR everywhere (assumption 1: Log reaches max size otherwise and skips my debugs) or setting it to FINEST (assumption 2: I should see more then) did not change anything.

This happened imediatelly after the Summer '13 Release.

I opened a case with Premier Support but I did not a response for weeks and regularly escalate it.

I thought I post this as an answer so I can use comments to keep you updated.

UPDATE 1: This only happends in Testclasses where I have many (20) test methods. Maybe thats the reason why the logs fills up with MUST SHOW stuff.