When the string in a field has unusual characters - for example Unicode 0x14 - the XML generated will be malformed & will result in a parseException with any browser set up to handle XML.

For instance, Apache Derby issue 246
http://issues.apache.org/jira/browse/DERBY-246?decorator=none&view=rss
results in the following display:
XML Parsing Error: not well-formed
Location: http://issues.apache.org/jira/browse/DERBY-246?decorator=none&view=rss
Line Number 269, Column 102:
when viewed using Mozilla (1.7.1)

Also, trying to parse this with a SAX parser results in this:
org.xml.sax.SAXParseException: An invalid XML character (Unicode: 0x14) was found in the CDATA section.
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at javax.xml.parsers.SAXParser.parse(SAXParser.java:345)