I've been running 1.21NA since roughly the time of its release. Not only would the router lag and lock-up (especially when attempting to upload large files, such as attempting to upload video to YouTube), but it would also occasionally cause my cable modem to reset. I had to unplug my router about once every 48 hours or so. Not wanting to risk installing the beta firmware, I scoured various different forums, and have found settings that make the router very stable. I've disabled DNS Relay, WISH, and GameFuel. With all of those disabled, on 1.21NA, the router is behaving better than it ever has before, and I've owned it for almost a year.