virtual pc "Use Physical Drive" grayed out

A few hours ago I downloaded virtual pc 2007 and decided to try my new vista ultimate.

The download and install of virual pc was quick and easy, and a very short time afterwards I had a virtual machine ready for the installation.

Well, as far as I could tell, the next thing to do was to put the vista cd into the DVD and boot the VM.

hmmm..
That didn't seem to work that well.
What am i missing? hmm...

A quick look at the PVC2007 menu and I saw I have a "Use Physical Drive F:" in there (which is my DVD) but it was disabled.
hmmm... again.

Another quick look and I see a CD icon at the bottom.
Now that took me for a short ride down the settings of the VM where I had the option of choosing between my primary or secondary IDE controller.
Nither made things better.

Well, It took me about another hour until I realized what was the real problem:
My original genuine fresh out of the litle plastic box with all the holograms and stickers aroundit vista ultimate dvd was just not working.
Had nothing to do with virtual pc.
but hey, it would be nice of VPC said something along the lines of "No media found" or something like this, and not just give me the impression that the problem is with not being able to connect to the drive itself.

I hope that if you are reading this it saved you some time,
go ahead, check your media - does it work on your host machine !?

(b.t.w. - I got the vista together with some more MS software - office 2k7 and such,
so when I found out that the vista DVD was f$&ked up I went along and checked all the other DVDs. No problems there... it was just the two copies of vista. I guess they come from some faulty batch. Now I have to contact MS to get a replacement ...)