So i'v come to realize after using the phone since late December 2010, that this is a normal new feature added to the phone. I have a 9780 on Rogers Wireless network. So i'm not sure if it's phone dependent but anyways. those 4 buttons stay lit after i use the phone. then later on they will turn off. I'm not sure if it's normal but my phone has been doing that since i first took it out of the box.
Other then that I love this phone. But I got it for free. I wouldn't pay for the 9700 -> 9780 but if it was 'offered' I would upgrade. 9700 leak or .. "official" users aren't missing much feature wise. My previous 9700 had major memory problems and i had to downgrade back to 5.0.