Spell Guide Beta-0

[lch]

This workaround resets the whole formular, though, all the values are reset to zero. Don't use workarounds as solution.

If you want to have it working in Mozilla, then you should have read how Mozilla handles these things first. Your first problem is already mentioned in there:

Mozilla requires that you send the XML and XSLT files with an XML mimetype (text/xml or application/xml). This is the most common reason why XSLT won't run in Mozilla but will in Internet Explorer. Mozilla is strict in that way.

The second problem is that you're replacing a DOM node by something of a different type. If I am reading the last paragraph in that article right then you can probably use transformToFragment() to have it working correctly. You are trying to put a DOM document into another one, not good.