Why libpq++ and testlo fails ?

Hello !
 I am using PostgreSQL 6.5 and RedHat 6.0. I compiled the whole
PosgreSQL, started the postmaster and edited some tables and runned
testlibpq0-5 from
examples directory under libpq++. Only the testlo fails to

ERROR: Connection to database 'template1' failed. PQsendQuery() -- There is no connection to the backend.
 (cmd: ./testlo template1 test tset)
 What have I done wrong ?
    Thank you very much,        Mika Saari