I have problem to reproduce this error, so far with the new GENA release i tested a lot combination and all work well
The link you gave, describe overwriting bootstr.dll.mui with one of the Win7 beta files. I can figure that it will be a solution nor that it would be good since you use Vista.
the good thing so far: the error message(s) are not critical and should not cause a problem for booting the new Windows installation.
Have not much time currently, but will continue trying to find a solution.
Maybe you can try to describe how you create/boot your GENA. Made special GENA support topic --> WinNTSetup2 script
This post has been edited by JFX: 11 August 2011 - 09:11 AM