I see what you are saying. My ISO is 4.55 GB (4,895,932,416 bytes) and is to large to fit a single layer DVD. I'm unsure if any internal files are to large. The apply rebuild thing still has me questioning whats going on. The apply (rebuild) is only used to rebuild after removing components correct? So it looks to me there is no way to make all version sp1 DVD using Vista x64. I'll just have to settle for a one version DVD I would guess. It seems funny that sp1 would be so much larger than RTM. Did MS go to a dual layer DVD for sp1 or is the slipstream leaving unneeded junk around? I'd try burning to a dual layer DVD if I had one.