This happens to me frequently from game to game on my Vita. Like Superstardust and get my high score and surprise its not being recorded as my high score with the SEN.
I see it when I start up on games in the top left warning me that I am Not Connected Error!
Is there something we should be doing to be logged in for the game?
Like pull up friends list or something with the SEN?
Unfortunately this is not an error but built into the games. I think it actually is a really dumb idea. The only 2 games I've seen it in is Uncharted and the single player portion of Super Stardust. The developers programed it to do that since it's a single player experience and doesn't need to be online. The stupid part is that you can't cross game chat with games that do this which is really dumb.