Hi Vix and welcome to the forums!
If the software home key no longer functions, this indicates (to me) a bad OS download. Not sure where you are, where you got the phone or what sort of warranty you have, but this is hinting at a re-flash of the operating system. IF you can take it back, perhaps they can re-flash 4.0.4 for you. Shouldn't take long... and you might get bumped up to 4.1.1