Firstly, thanks to crarko for nicely marking up the hint. I really must learn to do that one day.....

The unlock utility looks nice and definitely easier than following the hint.

For people who still want to use the hint to make it more secure chmod 600 /Library/LaunchDaemons/filevault2.unlock.plist so that only root can read the file.

I have a 40GB Windows partition at the end of the secondary drive. Apart from having to use the diskutil command line to shrink the encrypted partition and manually creating the Windows partition it works just like a normal bootcamp partition. This partition has been swapped between Windows and OSX a couple of times. When it is an OSX partition it detects the two encrypted partitions and prompts for a password. Windows just ignores the encrypted partitions (although they can be seen in disk management).

Thanks for the feedback,

Regards,
rakmod