iPhone 4 Home button issue...

I have tried to read on here and find out if anyone is having any home button issues but I can't seem to find anyone with the issue I am having. When I press my home button it works about 95% of the time. However, about 5-10 times a day it will not register the push at all and I have to push it again and it works. It's not something that really bothers me its just rather annoying. Anyone know anything about this? Also, has anyone noticed when you do push the home button it takes just a couple more seconds to close the app than the older iPhones? I have a 3G still and when I push the home button it instantly goes to the home page. Its just a little delayed with the IP4. I have compared it several times. Does anyone else have this issue? I'm wondering if its all just my phone because I haven't been able to compare my IP4 to anyone else's. I'm just wondering if all of this is any reason at all to get my phone replaced. I'm thinking it's not at all but I am just wondering who all else is having a problem or noticing a delay. I don't have any other issues with my phone. Just the home button. & if it helps any I have had my phone since day 1 of launch. I pre-ordered it.