You do not need to be logged in to PSN to get updates, you only need to be connected to the internet. So even with KMEAW 3.55 you will still get game updates as normal.
As far as the blackscreen issue goes, try fixing permissions for it (R1) and make sure you have the most recent version of Multiman. If that does not work, check out the game compatability thread or try re-ripping the game
Before you insult someone, walk a mile in their shoes. That way, you are a mile away and you have their shoes!