I had the same problem with a 1230 AP, I upgraded to the latest code and it worked. Before the upgrade I added the command "no dot11 igmp snooping-helper", not sure that is needed or not.
I went from version "c1200-k9w7-tar.123-8.JEB1.tar" to version "c1200-k9w7-tar.123-8.JEE.tar".
After...