createuser problem in 7.3.4 on Linux

I have been following the basic install process for Linux.<BR>
<BR>
As user postgres I have run initdb. I create a user named Administrator via the createuser script. All goes well and I get the response CREATE USER.<BR>
Then I try: <BR>
<BR>
psql -U Administrator template1<BR>
<BR>
and get the response:<BR>
psql: FATAL: IDENT authentication failed for user "Administrator".<BR>
<BR>
<BR>
The user Administrator is however in table pg_shadow.<BR>
<BR>
But if I try DROP USER Administrator&nbsp;&nbsp;I get<BR>
<BR>
ERROR: DROP USER: user "administrator" does not exist<BR>
<BR>
Note the last error has "administrator" rather than "Administrator".<BR>
<BR>
Does anybody have any idea what is happening? If not, does anybody know if it is possible to undo the initdb, so that I can create a new Linux user Administrator and use it to create the database via initdb?<BR>
<BR>
<BR>
<BR>
Any help will be much appreciated,<BR>
Paul Power <BR>
Planitas <BR>
Swords <BR>
Ireland <BR>
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