jbpm-bpel-1.1.GA was upgraded to support the final BPEL 2.0 standard not long before its release date. Due to time limitations, however, the examples were not upgraded as well. We have fixed them and the corrected versions are available from CVS.
Note that you do not need to check out the entire repository, just the files in the bpel2 directories. Then overwrite the corresponding files in the distribution.