I've several times been hit by strange behaviours of XSLT with XPath expressions involving elements in the default namespace, when this one was actually defined (e.g. <foo xmlns="http://foo-ns">). These expressions where not matching whereas using a prefixed namespace declaration would work.

I thought about a Xalan bug and always ended up using prefixed namespaces instead of the default one, without looking for a further explanation or bug fix.

This is actually not a bug: XPath doesn't consider the namespace declaration of unprefixed elements.

You never stop learning...

Via Dave .