Home Button partially work after replacement

Hello, I have recently replaced my mid frame and home button for my iPhone 3GS. The problem occurred after the replacement, the home button works, but it gives me weird click (Not a clean click), it only works on bottom half of the home button, and it is little wobbly which used to be very tight. I changed home button back to my Apple's original part but the problem still occurs. Does anyone have a solution for this?

Also, I would like to know if you need adhesive for home button after replacement.