G'Day Paul,
I had trouble updating to 8.0.1 too. I have stopped at 8.0.0 at the moment.
You are on satellite aren't you? I have suspicions that satellite is not as reliable as ADSL for downloads. A significant number of email attachments and downloads that I make are corrupted. The downloads this is easy to prove, by simply downloading again - it's often OK.
A 68M download of iTunes has significant room for corruption on a satellite link (yeah, I know they shouldn't... but that's what I experience).
If you can't get an install disk, get a friend on ADSL to download and burn a disk for you. I had to give up on the latest Virtual Moon Atlas: no way could I download it and get it to install... so I just ordered the disk
. With satellite hitting you for both uploads and downloads, and then downloads come through corrupted, it's just not worth the aggravation.
Al.