Java UnsatisfiedLinkError exception when connecting to Postgresqldatabase

Hello;

I've written a Java program which uses Postgresql via JDBC.  The program works fine on all RedHat systems I've tested
exceptone, where it yields an UnsatisifiedLinkError.  Here is the stack trace:
 

sun.misc.VM.latestUserDefinedLoader0(Native
Method)
sun.misc.VM.latestUserDefinedLoader(VM.java:411)
java.io.ObjectInputStream.latestUserDefinedLoader(ObjectInputStream.java:2351)
java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:686)
java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1866)
java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1749)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2040)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1571)
java.io.ObjectInputStream.readObject(ObjectInputStream.java:431)
org.postgresql.ds.common.BaseDataSource.readBaseObject(BaseDataSource.java:1210)
org.postgresql.ds.common.BaseDataSource.initializeFrom(BaseDataSource.java:1220)
org.postgresql.ds.PGPoolingDataSource.initialize(PGPoolingDataSource.java:267)
org.postgresql.ds.PGPoolingDataSource.getConnection(PGPoolingDataSource.java:324)

Any ideas?

Thanks in advance.