Well, for one thing, I noticed you are talking about the Ultimate Boot CD and not the Windows Ultimate Boot CD. Please realize that these are two completely different projects and this site and forum are mainly dedicated to the Windows Ultimate Boot CD. We do have a section in the forums here though for the UBCD so I'm MOVING this TOPIC there.
As for your question, I'm not sure why you are getting that error message. That seems like you may have a corrupt registry or mbr or something, I'm not sure, though I thought the UBCD bypassed that all. Did you make sure you downloaded the UBCD v2.4 with a download manager just to be sure the download was not corrupt before you burned it to a CD? Hopefully someone else has some info too.