Parallels 4 don't see BootCamp volume but VMware does

I've just upgraded today from v3 to v4 and can't start Windows XP from my BootCamp any longer.
I have Windows installed on a separate disk and under v3 I used an entry of "Disk 0:0 image = Boot Camp;disk2s2"
When started v4 I selected to convert my previous setting but Windows does not boot.
I'v tried to define a new Virtual Machine, but the option of using a BootCamp volume is greyed out.
I can use BootCamp in Apple's System Prefs to select it to boot from and I have been reading several threads here to find an answer. I have found some clues, but they all point to a file called "DiskDescriptor.xml" and that is not present on my machine. (And yes, I've looked on file content.)

 

Hello,

If you have a virtual machine which uses Boot Camp as a hard drive which fails to start after the upgrade from Parallels Desktop version 3 to version 4 and you are able to log in Boot Camp directly, please, recreate this virtual machine.

You would not loose any data, as only configuration files will be recreated.

To do this, please,

1) Launch Parallels Desktop from Finder -> Applications -> Parallels Desktop - > choose File ->
New -> Virtual machine from Parallels Desktop top menu. The installation Assistant will guide you
through the process.

2) Select "Custom" option in Virtual Machine Type window - > choose "Boot Camp Partition" when asked about
hard disk options.

 

As you can see from my original post I have already tried to define a new Virtual machine.
The problem is that the "Boot Camp Partition" is greyed out as an option! Hence I have no way to choose the disk where Windows is installed.
I've installed VMware as a trial, and that recognized the volume and I am able to run from my "Boot Camp Partition".

 

This is definitely an issue with Parallels 4. You can see my long story with this same issue: http://forum.parallels.com/showthread.php?t=88739.