No dice, I'm afraid.
Same wifi cutout issues on my WRT3200ACM, even with the older firmware - phone will be connected, but can't access any websites, nor load 192.168.1.1. Turning wifi off/on again on phone fixes the issue.
Sometimes the logs show deauthenticated due to inactivity (timer DEAUTH/REMOVE), sometimes they don't.
Going to reboot back into my previous image/partition that's running the newest firmware, since running the old seems to have done nothing.