When to move down

[InfernoLL]

Ok, this might have been covered before but I haven't seen it, so here's my question.

How much do you have to lose at the next level up (limit) before you move back down when bankroll is not a factor? I realize that I should probably just examine my game and keep playing until I start to win, but while I'm not risking my bankroll, it kind of sucks to keep losing. The other problem is that I'm moving from full ring to short handed, so I don't think playing the lower limit (which I'm beating) more will really improve the skills I need for short handed.

Another thing: how do you determine how much a loss over 5k hands or so is bad play or bad luck? I know that many more hands are needed to say anything significant about my game, but by the time I played that many, if I kept losing I might actually lose a substantial portion of my roll (I'm not psyched about trying to play 100k hands and losing 20x as much). Until a decent rush over the last 2 days I was losing at b/w 3 and 4 BB/100 after about 4.5k hands. At that rate I would lose something like 3000 BB after 100k hands, not desirable.

I ask this because my aces shorthanded have only been winning 59.26% and kings 68.42%. My friend who plays the same limit says his aces are around 80%. Also, if you're wondering, I'm not folding AA too much, I virtually always see a showdown with it unless something ridiculous happens (like 4 straight or 4 flush board in multiway pot w/ lots of action).