We have been using the WIFI calling (UMA) feature from our home due to poor coverage in our area. I have the T-Mobile branded Linksys router and we have been using Nokia 7510 and Samsung t339 phones. It has been working well and the phones auto linked to the router when we entered the house. I just bought an unlocked HP iPAQ 510 Voice Messenger on eBay and have been trying to get it to work. It works over the air fine (when I am out and about) but will not link to my router via the UMA at home. The phone sees the router and shows a strong signal but will not connect. Since UMA is working with the other phones I assume the trouble is in the phone setup and not a router issue. The Home screen shows the WIFI on icon but the screen says "No service" this is the over the air indication. The screen also says "Internet calling not available". I assume it is something in the setup that I have not optioned correctly. Here are the setup options: Internet / private net. Authentication; open / shared / WPA / WPA-PSK / WPA2 / WPA2-PSK Data encryption: disabled / WEP / TKIP / AES Network key : -blank box- Network index: 1 / 2 / 3 / 4 Any insight into this would be deeply appreciated.