2 trips to the verizon store, several weeks waiting for a replacement phone and hours of googling has gotten me nowhere - hopefully someone here can help.

As long as I've had my Gnexus (about 6 months), I haven't been able to leave it in LTE mode (so I get no 4g). When I do, my phone will display a great signal, but as soon as I try to download something, use the browser or make a call, I drop to no signal. Often, the signal will come back after about 30 sec, and then I'll be able to do a bit, but i will inevitably lose all signal again within a few minutes.

This is not an issue of coverage, I'm in a major city, and my girlfriend's phone (droid x) on the same network does not have this problem. I've tested it by having our phones side by side and doing the same thing - my phone drops the signal, hers does not.

If I leave the phone in CDMA only mode, I have no problems, but I'm limited to 3g. Verizon has tried giving me a new SIM card, I've tried factory resets, I've tried flashing jellybean, locked or unlocked, rooted or not, nothing seems to make any difference. Finally, thinking it might be an antenna issue, Verizon decided to send me a new phone. I just put in the new SIM card and booted it up - same problem.

I'm at my wit's end here. Any suggestions or even explanations would be appreciated.