Trouble with Booleans - Vanishing

Hello folks,

Sorry to post such a common question but trust me, I have tried everything
suggested to fix the vanishing polygon problem. I've checked normals and cleaned
up... I've done everything!

I am trying to make an Xbox 360. I made half of the front with a polygon plane,
I used the ten subivisions for the length, which was appropriate, however I also
used ten for the width. I think that's what my problem is as when I try to make
the little round recess where the power button is, 
by using a boolean function with a sphere, both polygons disappear.

When I made the face I extruded back in one big leap, then I used my subdivision
vertices to get the shape correct before mirroring and getting what looks to me
to be a nice looking model... apart from the whole not wanting to boolean
thing!

I also suspect that the fact that the rear of my model (as shown in the
attachment) doesn't seem to register as having faces could be the issue,
although it looks fine with the
 default shader on. (The render of the rear looks quite aliased, but I assumed
that would be fixed when I did some "real" rendering).

I have attached my file,  I would appreciate any help with this problem!

I am using Maya 6

Owen.