Bayern seem to concede from corners a lot.
That's obvious. Neuer's weakest point are corners - he often rushes towards the ball and sometimes misses it or punches it out badly, leaving the net wide open. Also, he likes to show off - he has great ball control, but sometimes he thinks he's Ronaldo and starts dribbling around his own box. Arsenal managed to take advantage of that 2 times against Bayern. Especially, look at the Podolski's goal in Emirates - what the hell was Neuer doing? Defenders didn't do their job, yes, but he was completely clueless too. Another his fail was in Germany's match against Kazakhstan - once again, he tried to dribble and lost control of the ball, letting in ridiculous goal.