iPhone 3GS digitizer not working

I bought an iPhone 3GS that was not responding to touch. I bought a new digitizer and replaced it all without a hitch. When I tried to use it, I found that about a centimeter of the digitizer on the very bottom doesn't respond to touch. I can slide the unlock bottom just barely, but anything lower than that can't be touched. I know that this is probably a digitizer problem, but I bought it from PhoneDoctors and I would expect it works....

Any ideas?