Content is not allowed in prolog - JMeter server

Hello,

I have a test that uses XPath extractor to get some data from XML response.
When I run the test in GUI - all works fine. When I run the test using JMeter server and as master I use GUI - all works fine.

When I run the test using JMeter server and I start master from command proms - the following error appears (on slave):
2013/12/17 09:58:09 ERROR - jmeter.util.XPathUtil: Type=Val=false Tol=false org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.
2013/12/17 09:58:09 WARN - jmeter.extractor.XPathExtractor: SAXException while processing (//xmldata/auth[1]/@session) Content is not allowed in prolog.

Batch script used:
jmeter -n -t c:\Pulse\trunk\Testing\Performance\jmeter\pulsePerformanceRT%6.jmx -Jrev=%1 -Jsrvadd=%2 -Jportnum=%3 -Jprotocol=%4 -Jenv=%5 -r

Is that a JMeter server issue or do I have to change setting of some processor?

All used machines are running Windows.

Thanks for help,
Filip