I'm running iOS 6 beta 3 on my iPhone 4 (GSM). Anyway, I'm having a couple big issues. I know it's a beta but am curious if anyone else is having these issues or knows of any fixes. I never had issues on the first 2 betas but are having big issues on beta 3. First of all, MMS doesn't work on AT&T's network anymore. I tried resetting network settings and restoring to no avail. And the other big issue are random freezes. For whatever reason, sometimes when navigating through the UI, my phone will become completely unresponsive for 10 seconds or so. Is anyone else having these issues and do you know of any fixes?