I just saw a really handy tip on the Oracle User Group. NetSuite saves past revisions of Advanced PDF/HTML templates, and you can get back to an old version by adding

&version=_<previous version number>_

to the url. At the bottom left corner of the page you can see which revision you are currently on

gone are the days of saving the old version to notepad++ aand seeing if it works!

I still save my production versions out to separate files. I've seen strange behaviors in the past where edits suddenly disappear.