Just got a new Lenovo Ideapad Z580 that has Windows 7 64-bit Home Premium installed. I would like to Encrypt it with TrueCrypt as well as install Kubuntu also encrypted.

According to:

I resized windows and installed kubuntu encrypted and all works well.
I ended up with 4 primary partitions: windows boot, windows system, ubuntu boot, ubuntu system (LVM/LUKS)

Now I'm supposed to, from windows, encrypt the windows system partion and let TrueCrypt overwrite grub with it's own loader. TrueCrypt gives me the oportunity to test it's new boot loader without actually encrypting the drive. Doing that the boot loader loads up, accepts my password but gives me the following error:
Error: No Boootable Partition Found
Any ideas?
Thank you.