Google Drive app on Nexus 7 doesn't allow offline editing

Okay, so I have a problem. I have a Nexus 7 (rooted, unlocked bootloader, but no other changes to the system). I have a few google documents (native gdoc format, I'm the owner) that I'd like to edit in my spare, off-the-net time. The problem is, when I select 'make available offline' in the application, the document appears in the offline tab, and I can edit it as long as I'm connected to a network. When I disconnect, wham, offline documents are set into read-only mode, I can select text, but I can't do anything else (also, there's that blue-ish bar on the top with ios-like "all docs" button). So, what's going on? I really need to be able to edit some documents when I don't have an internet access.