Problems started as i wanted to config another user on the database server for SQL*PLUS Access. Even my setting of LD_LIBRARY_PATH/PATH/ORACLE_HOME was correct i got following message starting SQL*PLUS :

sqlplus: error while loading shared libraries: libsqlplus.so: cannot open shared object file: No such file or directory

The reason was the setting of the priviliges of these very important oracle runtime directories

drwxr-x-.-.-  3 oracle dba  7184 2006-11-03 15:16 lib
drwxr-x-.-.-  3 oracle dba  5144 2006-11-03 15:16 lib32

to access these directories you must at least in the dba unix group. I wondered about it. Probably an initial umask setting of the oracle user?

[ svx66287 /opt/oracle/102 ]
 ISISP [102] oracle > umask
0022

As workaround i put the user into the dba group which is not very secure. if you have any idea please let me know. As is said all works fine with the oracle user.

Karl