md5 authentication fails

I have pg 7.3.2 running on rh8 2.4.19.
I have pg_hba.conf with line
host testt user xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx md5

I can log on as user thru psql -h xxx.xxx.xxx.xxx testt
pgsql asks for password, allows logon to testt

I have a java program using user password that gets
authentication failed for user user error

username and passwd are the same as used in psql
on another machine the java program works ok
something is not set up right on the box that is failing

I set up the good box by trial and error, hacking/stumbling around until
something worked, then stagger on to the next debacle
no clue to what the difference might be

Any suggestions greatly appreciated

TIA
rfjones