home button does not work properly after replacement

Hi everyone. I had an issue with my home button. I ordered the home button package from this website and replaced it couple days ago. But right after replacement started noticing weird phone behavior - the button worked fine when I clicked it but time from time phone was clicking the home button on it's own without my mechanical help - I mean when I even don't touch the phone it's executing the home button click. Have no idea what is wrong - was fully following the manual - maybe software issue?

My firmware is still 4.0.1 and the phone is jailbroken.

Thoughts?

 

please, reply anyone who has at least some guess what could cause this strange behavior