The postgresql-data rpm that I have always seen on previous releases of your software is not on the 6.0 CD. When postgresql is started it aborts with an error about no data directory, so I assume these two things are related. I downloaded an rpm for postgresql-data from rufus.w3.com and installed it. Now postgresql works as expected. Just thought you should know
*** This bug has been marked as a duplicate of 2721 ***
*** Bug 2924 has been marked as a duplicate of this bug. *** The package "postgresql-data" is missing, even if it is cited in "postgesql" package docs as useful for novice users.