Fedora 9: Mixed fc7 and fc8 Packages

When upgraded from fc7 to fc8, there were hundreds of packages still there from fc7 and some from fc6. Most of the them are duplicated. I had several repo's, and upgraded one by one. I wonder if that was the problem.

For fc9, I update all the yum repo's to release 9 before running yum update.
Right now for fc9, I only have handful of fc7 and fc8 packages.

Also run:

package-cleanup --cleandupes