Trying to move up to 1/2

[brentlip]

Is 1/2 much harder than .5/1? I recently tried moving up and I didn't do to well (-1.27BB/100 for 8500 hands). I've been doing great at .5/1 (3.71BB/100 for 10,700 hands) and I'd just like to know if this could be variance? Did I try moving up too early? Could my win rate at .5/1 be variance? It seemed that the games were a little more aggressive. Should I adjust my stategy a little next time I try and move up?

Thanks,
Brent