Home button not working after display assembly replacement

I had a cracked screen so I replaced my iphone 4 lcd/digitizer front assembly and home button using ifixit parts and guide. I replaced the home button because I decided to put on a white front assembly rather than black (and thus got a home button to match). I followed the guide and everything works great EXCEPT for the home button. It doesn't work at all! I took the phone apart again to make sure there wasn't anything weird going on w/ the home button or home button ribbon cable and everything looked fine. It does seem like the home button sits deeper (further recessed from the front panel) than the original. Am I missing something? Is there a common issue with this that I should check for?