mkdir:"a/var/sadm/launcher":I/O Error
This looks like a probable hardware error. Somehow, it decided to create a directory in an unexpected place (a/var/sadm/launcher). It's the "a" on the front that makes me suspect that, since /var/sadm/launcher is OK.
You might want to run a memory
test and a disk check. There's an excellent memory test program that comes on disc #1 of any of the recent Fedora install CDs. For a disk check, probably a booting copy of Knoppix is the easiest way of geting a linux system temporarily booted so you can run the badblocks utility. Since you're doing a system install, run the full badblock test (including the destructive write option) unless you're setting up for a dual boot environment and don't want to wipe out the other partitions.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.