That is odd, but I’ve had similar experiences (once or twice) attempting to install Linux on older machines.
Well, it didn’t help my being a total n00b with Linux.
I ran the hash against my DVD image, and got the right numbers, and the DVD (the LIVE/install version) boots just fine, and I can play around with all the cool toys.
I just can’t get Install to progress beyond the 15% mark once I’ve specified the drive partitioning, and it didn’t make a difference whether I tried it Guided, Guided Whole disk, or Manual.
I even played around with QTpart trying to set up the partitions BEFORE I initiatied the Install & still got no play.