According to what i've read between Scrypt and Skein, 1mh (scrypt) is equivalent to 300mh (skein).
We have a median of 100mh on p2pool scrypt and 3gh on the skein p2pool. (just taking p2pool stats)
So 100mh scrypt is equivalent to 30gh skein if i'm right, so we have 10x time more power on Scrypt p2pool but we find much more less blocks on the Scrypt p2pool than Skein p2pool.
Correct me if i'm wrong but if i'm right that mean Skein is much more easier with 10x time less power... so their might be a problem with difficulty retargetting on Skein