Thanks everyone who replied.
2010/2/25 Dinesh Shah (દિનેશ શાહ/दिनेश शाह) dineshah@gmail.com
The issue is resolved. The problem was corrupt yum repo DBs. Here is what I did to resolve the issue.
$ sudo yum clean all
$ sudo yum clean metadata
$ sudo yum clean dbcache
$ sudo yum makecache
$ sudo yum update
$ sudo yum install dia
HTH \With regards,