Replaced digitizer, touch sensitivity works occasionally

I recently replaced the digitizer glass on my 1st generation iPod touch 8gb model. I was successfully able to remove the old one and install the new one and was able to get the iPod to turn back on. I did manage to damage the back metal panel on the top of the iPod by the screen lock button and the wifi antenna. However both still seem to be working properly. Anyway, it seems that the iPod will only have touch sensitivity for certain periods of time. During those times, everything works perfectly like it was new. After a random period of time or use however, it will proceed to lock up and not allow any touch sensitivity at all. The only way to regain touch sensitivity is to lock the screen with the button at the top and then when turning it back on all touch sensitivity will return again but still for a random interval of time. I did reapply the firm ware to see if that was the case and have taken it apart several more times to make sure that all cables were connected properly and nothing was damaged. Is it possible that I have a defective digitizer?

Any help would be appreciated.

Adam