when I upgraded from Fedora 12 to Fedora 14, about twenty days ago,
the system (which wasn't doing really well even before the upgrade)
became almost unusable.
Weird problems often have a hardware issue behind them. There are many
things to check. Some are easier than others:
From the desktop, open the program System>Administration>Disk
Utility.
Select each of your hard drives in the list on the left, and then click
the
Smart Data button.
In the upper part of the window, look for a Bad Sector count, and Overall
Assessment of the drive.
Any problems?