I have UMA on my 8900 and use it extensively to save $. My phone also serves as my alarm clock meaning when I get a phone call/txt/important email I fully wake up
Some mornings I will have nothing on my phone except email. I will then go about my day, and until I make a phone call, which fails, realize that the UMA broke, turn off/on the wifi radio, and phone calls start working. This is a small disaster for me because my business depends on incoming calls. When the UMA breaks, it stops the phone from getting incoming calls (the UMA indicator is on the whole time btw)
While I'm sleeping the UMA breaks and the phone stops gettings calls, sms, bbm, etc. But it will usually get e-mail. I have att uverse with pretty fast speed so bandwidth doesn't seem to be the issue here. I do have a linksys wrt54gs with latest firmware (connected to uverse router through Ethernet) acting as a separate access point. That is obviously suspect but I'm not totally convinced. If the UMA stops working right, the EDGE should take over and allow communication but thats not happening in my case.
Any thoughts on why my UMA likes to break in the middle of the night 2-3x/month?