Sorry, I haven't checked this thread in a few days.
Make sure you have the antenna plugged into the port that looks like a satellite dish on it. There are two antenna ports on the UML290, and you want to be in the one with the dish on it. (See »3gstore.com/device/113_verizon_p ··· 290.html
Also, I set my UML290 to 4G only with the VZ Access Manager software.
What kind of antenna are you using? Do you get any better data rates if you drive closer to the tower?
You may want to make a new thread (just so you get more visibility with a more logical title) and post your issues with your SINR/RSSI numbers. Some of the folks here are very good at narrowing down signal issues.