Postmaster starting error

Hi,
   I have downloaded the postgres version 6.5.3 . My m/c is redhat linux 6.0.
   Postgres compiles without any error. I then initialize the database using
   initdb. But when i start the postmaster i get the following error message.


Database system in directory /tmp/pgsql/data is not compatible with this version of Postgres, or we are unable to read
thePG_VERSION file.  Explanation from ValidatePgVersion: Version number in file '/tmp/pgsql/data/PG_VERSION' should be
6.4,not 6.5. 

No data directory -- can't proceed.


    Can anyone explain why?

   --
   Rahul Ravindrudu

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   Rahul Ravindrudu
   4th Yr B.Tech
   CSE Dept, IIT Bombay
   Mumbai, India 400076
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