spawners seem to ignore light

I just updated my survival server to the latest snapshot 14w25b and I went to my skeleton xp farm and I herd skeletons but my redstone lamps were on.
the spawner worked in the prevous snapshot and it behaved like a normal spawner. I have not tested this in single player, I was on my survival server.

sorry the image is hard to see, tried my best to get a good picture.