To Joerg: the attachment is my enviroment ,still using xalan 2.5.2
I can confirm the error with XSLTC from Xalan 2.5.2, I didn't try it with XSTLC from Xalan 2.5.1 yet. But it works with Xalan 2.5.1 itself, so I can only recommend you to downgrade to this version.
Joerg
