Currently I have been migrating BPEL for a client using Oracle SOA Suite and ran into incompatibilities between 220.127.116.11.0 and 18.104.22.168.0. A simple example that worked in 22.214.171.124.0 and not in the latest patched released is a simple evaluation where I am trying to confirm the existence of an element in a message.
<bpws:getVariableData("message","part","/element/element")> = true()
The same statement also works in Cape Clear ESB and its BPEL implementation.
One workaround that I used was to count the nodes using the Oracle XPath Advanced Functions:
ora:countNodes("message","part","/element/element") > 0
I am working with Oracle support services to see how this can be resolved in the code base.