How do I fix a dead strip at the bottom of the screen?

My iPhone 3G had a cracked front panel as a result of a drop on concrete. The LCD was fine and touch sensitivity seemed unaffected. I used the phone normally, but it was difficult to see some parts because of the cracks.

I ordered and used the front panel repair kit supplied on this website. It was actually a bit easier than the Techspank video on YouTube. Everything seemed to be working for at least a few hours, or at least I thought so. I did not specifically test all areas of the screen for touch sensitivity.

The next morning, my phone was on the lock screen, but I could not slide to unlock it. I have since tried all of Apple's recommendations: hard resets, restores, etc. but nothing has worked. I've even put it in DFU mode, re-jailbroken it, etc.

It does not seem to be a software issue. I must have somehow damaged something during the repair.

My Questions:

(1) If there is a dead strip, is the problem the front panel assembly or is it the LCD screen? I would think it was with the front panel assembly that the glass attaches to, correct?

(2) Has anyone successfully fixed a dead strip problem with replacement parts? What parts did you order?

Note: My iPhone 3G is out of warranty and I assume Apple will not repair or replace it if they look for evidence of me opening the case or replacing parts.