Motorola Droid X :: Phone Suddenly Not Getting Signal

I must have the worst luck with phones. My Droid X was working flawlessly since I bought it last week and then suddenly won't get signal! I called VZW and was on the phone with them for over an hour. Tried everything and come to find out, my Droid Eris (previous phone) connects just fine. Some problem came up with the Droid X! Suffice it to say, they are sending a replacement in an week or two and I'm back to the Eris in the mean time. Anyone know how the heck this could've happened? I tried airplane mode on and off, turned the phone off and on, took out the battery while the phone was on, did a full system reset and went through all of the system stuff through VZW.