I ran into another issue near the end of my upgrade to Ubuntu 8.04 Hardy Heron.
After the packages were downloaded and installed I received a msg that I should restart my PC. But at the same time the installer showed 99% and an error that something was locked.
Anyway I restarted and I guess now I'm proudly using the Hardy Heron :)
I don't have any problems after the upgrade. I tried Compiz but there were the standard issues with its integration with KDE, so I turn it off. I can't see any differences in performance too.
Soo the next big upgrade I'm waiting for is KDE 4.1, because the 4.0.x still have many issues.