wl1271: communication fails with kernel 3.4-rc2 and firmware series 4

I have a problem with WLAN driver wl12xx and 3.4-rc2. I made tests both on AM3517 + W7310 and Pandaboard. Both have wl1271 chip inside. Previous kernels 2.6.37 and 3.3-rc7 made no problem: I could associate with my AP and then reach every host in my LAN. With 3.4-rc2 I can only associate, but IP pings can't be received/sent.

This is my discussion on linux-wireless mailing list:
http://thread.gmane.org/gmane.linux.kernel.wireless.general/88659

Am I missing some important patches? Can someone try and confirm my observations?

Thanks,
Yegor