[PHP] Method C14N from DOM

[QI.VOLMAR QI]

I've got this error:
*"Fatal error*: Call to undefined method DOMElement::C14N() in..."

My local server has the version 2.7.6 of libxml, and works fine. The
development server has the version 2.6.26
DOM/XML API Version 20031129.
This may be the problem? Or there's a dependency lost? or something like
this...