During the installation of Oracle 10g Rel 2 on Linux this error may appear because the required library is not installed by default. Before installing Oracle, you must make sure all required packages according to the installation guide are present.
There are two libraries which are not installed by default in OEL5, libXp-1.0.0 and compat-db, these files are found on Disk3 in OEL 5.2.
The command used to install the required RPM's on OEL 5.2 is:
rpm -ivh compat-db-4.2.52-5.1.i386.rpm compat-libstdc++-296-2.96-138.i386.rpm compat-libstdc++-33-3.2.3-61.i386.rpm gcc-4.1.2-42.el5.i386.rpm gcc-c++-4.1.2-42.el5.i386.rpm glibc-devel-2.5-24.i386.rpm glibc-headers-2.5-24.i386.rpm libgomp-4.1.2-42.el5.i386.rpm libstdc++-devel-4.1.2-42.el5.i386.rpm libXpm-devel-3.5.5-3.i386.rpm
This assumes all RPM's are present on a stage area.