On Thu, Jun 21, 2012 at 3:26 PM, Pete Goodeve <pete.goodeve@xxxxxxxxxxxx> wrote: > Hmm. OK. I didn't realize there had been such significant recent > changes. I've made a new stick (hrev44242). Unfortunately the > changes are so significant that it won't boot on my current machine!! > (The boot icons appear, but none light up. Safe mode makes no > difference.) You're not the only one experiencing that... If possible, you should binary-search old revs until you locate a range that caused the bustage - very possibly it was the same IOAPIC changes that fixed things for other people. Some people have reported certain USB changes causing failure-to-boot as well... - Urias