when i tried to update a new install;

~]$ sudo yum -y update Loaded plugins: fastestmirror, refresh-packagekit, security Setting up Update Process Determining fastest mirrors
* base: repos.dfw.quadranet.com
* extras: repos.dfw.quadranet.com
* updates: repos.dfw.quadranet.com extras | 3.4 kB 00:00
extras/primary_db | 37 kB 00:00
updates | 3.4 kB 00:00
updates/primary_db | 3.7 MB 00:02
Error: database disk image is malformed
~]$

ran a web search, which produced ‘about 408 results’. skimmed thru them looking for a favorable url, which was;

forums.fedoraforum.org/showthread.php?t08521

which led to these 2;

~]$ sudo yum clean dbcache
~]$ sudo yum history new

system is now updateing without errors.

hope this is help to anyone who man have problem.