oracle 8.1.5 is an unstable version, if you have anything higher than this I sugget you use it.
As for your ???, here's how to do without axing you currentl lib. During the install when you encounter the relinkk err, open another xterm window and hack $ORACLE_HOME/bin/gencltsh script:
change LD_SELF_CONTAINED="-z defs" to read LD_SELF_CONTAINED=""