Zune HD Occasionally Not Responsive

I've owned a 32g Zune HD since release and i'm having a few problems lately.  Occasionally when i press any of the buttons to open the splash screen, the zune will not do anything.  in the dark i can see some of the pixels of the OLED screen shine, but the lock screen fails to display. i keep pressing buttons until something finally happens. this issue has occurred while playing music, without playing music, with wifi on, and with wifi off. sometimes while playing music, the device won't come back at all and i have to restart the device. also, occasionally my splash screen won't be responsive when i first active it. i have to give it a little time before i'm able to move it.

are all HD's having these problems? i'm wondering if these are hardware or software issues as well...
i understand newly released hardware often ship with problems.

thanks guys

Same thing happened to my HD.  The only way I was able to get the screen back was pretty much what you were doing (push buttons till something shows up).

More specifically, press the center button, then the power button, and then the center button once more and the "lock" screen always pops up.  Not a clue why this happens.. (This thing sure is a PITA to navigate while trying to drive, especially when this happens. The Zune30 was a piece of cake to mosey about the system with one hand and no eye contact...)