hi,
I had a similar error and found that when the file size exceeded a certain length in the loading process failed, fix changing ojdbc-14.jar version (the version that has the jbpm4.3.zip is 9.0.2.0.0) for http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/htdocs/jdbc_10201.html downloaded 10.0.3
And it worked.