ToB fixes all sorts of problems, and so does the
Baldurdash patch. the sword is immune to all forms of physical damage (eat THAT, stupid dragons!

) but not fire or acid, etc. death spell is good, so is death cloud, finger of death, etc. (or any magic)
you could always re-charm it, y'know. [img]graemlins/evillaughter1.gif[/img]
the baldurdash patch and/or ToB will also fix its AI so it never turns on you.