I don't think that of executing root.sh would solve this problem. It looks like the wrong libraries had been linked. Check them up and then relink the rdbms libraries
To do it, First shutdown all the instances.
$ make -f ins_rdbms.mk ioracle
This I hope would help to relink the libraries. In the mean time also check the oracle metalink, for the new patch for the intelligent agent. On such case follow the pathch installation and it would also cover the linkings.
Life is a journey, not a destination!