only intermittently obedient

Why would Crowley be in charge in Hell, just 'cause Lucifer got locked up in that cage with Michael? Wasn't Lucifer in that cage the whole time he was ruling down there? The whole point of the Ruby plot was to free him from that cage, was it not? Is his family feud so distracting that he can't handle the business at the same time?

EDIT: I found it! In the tv.com viewer-written episode recap of Hammer of the Gods is this decription of the boys watching a dvd left them by Gabriel:

The next day, Dean and Sam stop off to watch Gabriel's porn movie on their laptop. Gabriel is the actor in the movie, and then turns to tell Sam and Dean what the hell is going on. The pre-recorded message explains that he's dead and they've got no chance of killing Lucifer. However, he explains that the cage that they sprung Lucifer from can still hold him, if they can get the cage open and trick Lucifer back into it while avoiding the angels. Most importantly, the four keys to the cage are out there: the four Rings of the Horsemen. If they can get all four rings, they can contain him. Gabriel ends by admitting he was scared, but that now he's finally stood up to his brother. The brothers figure that they've already got two rings, and they just need the rings of Pestilence and Death.

He ruled from the cage before, so why not now? Unless it's just a lapse in logic by the writers, and I should just suspend my disbelief and enjoy the pretty already. :>