Yes. With a small vocabulary, it's very likely that the same hashcode will be allocated to the same name in both NamePools. If that happens, everything gives the appearance of working correctly - but the more the vocabulary grows, the more likely it is that clashes will occur.
Thanks for the quick response Michael; I will give the s9api a go.
Out of interest through;
Lets say in my case both factories where initialised using a different Configuration/NamePools. Why does it work in the second case (TEST_02.xml) and not in the first case? Is it pot luck?
In my original email, I gave a trimmed down version of the XML document (to make things easier) and the ‘problematic’ XPath mentioned was the only one to cause an issue. If I move the <swPrivateData> node to another point in the document, the XPath works fine.