I can help get this issue resolved. I researched and found no related issues in regards to 3G network issues. What areas are you traveling to with no 3G service? Does the service go out when you stay in a 3G coverage areas too? Verify the data in enabled under Settings>Wireless & Networks>Mobile Networks, also make sure Data Roaming is enabled.
While you are in a 3G coverage area, perform a master reset on the Vortex. Go to Settings>Privacy>Factory Data Reset>Reset Phone>Follow the on screen instructions and re-activate. Please make sure your info is backed up to Google or the SD card before doing the reset.
Keep us posted on this concern.
Did this right after I made this post. Probably 4 days ago now Also had to make sure that it was set for every trip not just the one-time trip. I haven't had a problem since I changed the settings. I live in the Wichita, KS area to answer your question. I was having problems even if I entered a structure and when I came back outside it wouldn't reconnect. However since I made the changes it hasn't been a problem. I also made the same suggestion to Dave1138 on his post yesterday. He has been having the same issue and did not want to recommend it until I had tried it myself. Haven't heard from him yet as to success. Thanks for your input I'm glad to see I was on the right track with it.