X51 R2 - strange startup freeze issue

I've had my new Alienware X51 R2 (i5-4460) for about a week now, and it's mostly working fine, except for this one minor yet persistent issue, which I'm wondering if anybody else has come across.

This is what happens: whenever the machine is fully shut down, the first time it is subsequently switched on, it freezes at the very first part of the boot up cycle, i.e. the screen with the alienware logo and the F2/F12 startup options (which should normally only display for a second or so). If nothing else is done it will stay on that screen forever so far as I can tell. What I then do is switch off with the power button, then switch on again, at which point it always boots up fine. So it isn't really a major issue, in that I can always correct it by hard-rebooting. But it is concerning because you don't really expect such issues with a brand new computer, and because it is so absolutely predictable - every time, like clockwork, when I start the computer up after having it switched off overnight or while I am out at work during the day, I have just gotten accustomed to the fact that the first time booting up it will get stuck and have to try again. It worries me not knowing why it is happening, and because odd unexplained glitches can sometimes be warning bells for worse problems on the way.

So does anybody know what may be going on here?

Thanks,