I have found also this one: http://apache-sling.73963.n3.nabble.com/jaxb-OSGI-amp-com-sun-xml-bind-Cannot-be-resolved-and-overwritten-by-Boot-Delegation-td4046690.html
As I am using a SAX parser I don't think I will run into some "OSGi-compatible concerning class loading" problems.. But WDYT, does it make more sense to rely on a working "SAXParserFactory.newInstance()"?