Urgent

HI,
Hi,I am using Redhat Linux 9, I need to uninstall postfesql 7.3.2 andi have to install postgresql 7.4.5. Plz let me
knowhow to uninstall 
completely - postfesql 7.3.2

if i install the postgreSQL 7.4.5 and i used the command,
bash-2.05b$ psql
psql: relocation error: psql: undefined symbol: get_progname

plz help me regarding this error.
"psql: relocation error: psql: undefined symbol: get_progname"


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Warm Regards,

S.ElayaRaja
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