seeking help with postgres installation and use

I have been playing with postgresql at home, working through a book on general database installation and use. Mostly is is an oracle book, but much of the book is easily translated to Postgres. This is on a fedora core 2 linux box, kept fully yum updated.

Here are the packages installed via yum:

$ rpm -qa | grep postgres
postgresql-libs-7.4.2-1
postgresql-server-7.4.2-1
postgresql-test-7.4.2-1
postgresql-7.4.2-1
postgresql-devel-7.4.2-1

Then I enable plpgsql:

$ droplang plpgsql template1
$ createlang plpgsql template1
$ createlang -l template1
Procedural Languages
  Name   | Trusted?
---------+----------
 plpgsql | yes

As user postgres I try and run the tests:

$ pwd
/usr/lib/pgsql/test/regress
$ time ./pg_regress.sh --schedule=parallel_schedule
...
====================================================
 6 of 93 tests failed, 1 of these failures ignored.
====================================================
...

$ grep -i FAIL ./regression.out
test create_function_1    ... FAILED
     triggers             ... FAILED
     plpgsql              ... failed (ignored)
     copy2                ... FAILED
     rangefuncs           ... FAILED
test stats                ... FAILED

Here are some results from the diffs:

$ grep ERROR regression.diffs
ERROR: could not access file "nosuchfile": No such file or directory
! ERROR: Can't find function nosuchsymbol in file /usr/lib/pgsql/test/regress/regress.so
ERROR: there is no built-in function named "nosuch"
ERROR: could not access file "nosuchfile": No such file or directory
! ERROR: could not find function "nosuchsymbol" in file "/usr/lib/pgsql/test/regress/regress.so"
ERROR: there is no built-in function named "nosuch"
+ ERROR: language "plpgsql" does not exist
+ ERROR: function trigger_func() does not exist
+ ERROR: function trigger_func() does not exist
+ ERROR: function trigger_func() does not exist
+ ERROR: function trigger_func() does not exist
+ ERROR: language "plpgsql" does not exist
...

$ grep plpgsql regression.diffs | more
+ ERROR:  language "plpgsql" does not exist
*** ./expected/plpgsql.out      Wed Sep 24 23:58:06 2003
--- ./results/plpgsql.out       Mon Sep 27 21:11:32 2004
  ' language 'plpgsql';
+ ERROR:  language "plpgsql" does not exist
...

$ grep HINT regression.diffs
+ HINT: You need to use "createlang" to load the language into the database.
...

So I guess I am confused. I thought I added the required language (plpgsql) properly. Sorry if this is something obvious, I have googled several times and have not found much help for this.

Perhaps I should be building from source or using the RedHat "rhdb" iso?

Thanks for any hints,
John