Hello guys, I'd like to share my experience for the benefit of all the good people that had shared their knowledge to solve this particularly uncomfortable problem.
I had problems with my home button for the last year and applied pretty much all the tweaks described in this thread, all of them worked, to an extent, and none of them were definite. Finally I paid a technician to replace the button and he explained to me what happened to my unit (and possibly to all of you who are experiencing the same problem):
The button part has an integrated circuit that in my case was partially "unglued", the most common cause for this is contact with extreme humidity or water exposure, this hardware error cause the button to be faulty, and by using the power cable or cleaning with isopropyl alcohol, you are only pulling the circuit back to place, so it can work temporarily work until it moves out of position again. The technician simply replaced the circuit and welded it into position and the button has been working like new.
I recommend you to visit your local phone technician and asking about a fix, I paid under $35 USD for it, and since my iPhone was out of warranty I even feel more secure after the process, knowing that if I have a hardware problem again there is skilled people that will fix your problem and treat your unit with care.
Hope this help. The best of luck to all.