Here's the real skinny folks.
I had a Fam Pack sent out on May 16. Installed it on A Tiger Mac Book and it went in like hot butter on warm bread! Tried to do the same on another MacBookPro with Leopard ( 10.5.8 ). Nothing but problems. "Clean CD", followed by numerous restarts. "Can't install "support files"...yada yada yada.
Booted to the CD..after 10 minutes...same garbage.
Called Apple Support.....they sent me a brand new CD overnight. Same problems with the new virgin CD!!!
I'll skip the support call again where a nice guy named Jake walked me through the process. Same stuff...failure.
Here's what I discovered.
1) I had Bootcamp on the install partition.
2) Appparently Snow Leopard does not like that.
3) Deleted the partition and reinstalled Snow Leopard. After 55 minutes or so...success!
4) Ported over all my apps from a USB backup. Not a problem.
5) Used Bootcamp to make the same size Windows partition.
6) Used the Windows backup image to restore Windows.
7) Bingo.
Apple support has no idea that Bootcamp is the culprit.
Hope this helps.