Your response helped. I am now able to pinpoint the specific strings in the XML files that are causing the errors. However, I can't yet understand why it's causing the parser to fail.

The XML files have embedded &#32 entities in the data elements. Every space in every data element has been rewritten to &#32. I can't yet associate any specific context that causes the failure but not every instance of the &#32 fails (only 1 or 2 out of several hundred in the file). Strangely, in the specific instances where I do get a failure I can substitute a literal space and prevent the failure for just that specific instance. If I try and replace every &#32 with a literal space the parser has even more problems.

Any ideas ??