This is my experience that i have:

after I do a full reflash with both firmware and EMMC. The first thing I go to install is meecatalog. Then I enable all extras repository in the settings. Afterwards, I want I cant download or install some Apps in store, like: Gpodder, Mieru, Apps for Meego...it said installation interrupted.

Therefore, I try to find out what is the cause, it is because I have enabled the "Harmattan developer repository" in settings in Meecatalog, I disabled it and I can install or download things in the Nokia Store.

Hope this can help you.