DS 6.9 SP6 - WinPE 4.0 error

No matter how i've tried to install WinPE 4.0 as a pre-boot operating system it continually fails with 'Missing Operating System Files'.  I've tried using the adksetup.exe and i've also tried using the option for the pre-installed ADK and both give the same error.   Previously with 2.1, Altiris had their own exe's to install this.  Using the Windows adksetup seems to be buggy.  Anyone have a solution?

Thanks!