Element Cleanup in HTML Editor

Hi – I am competent with editing HTML code and have always used the comment feature to control which elements of my website are live at a given time.

I recently switched to using WordPress and have noticed that the editor goes nuts when I insert a comment tag. Not only does it edit the other tags nearby – adding extra tags where they aren’t needed. (example: when I comment out a single list item, it adds multiple open and close UL tags surrounding that area.) Also it seems that more than necessary (several other lines are just NOT there when I load the page) actually gets commented even though I have triple checked my code.

In searching the support forums it seems that WordPress employs some sort of “element cleanup” I assume as a way to “idiot proof” their editor. Unfortunately it is wreaking havoc on my site. All of the support entries regarding this are 1+ years old and seem to reference editing a format file that I can’t find and assume has been relocated in the WordPress interface.

Any suggestions for how I can make the editor not “fix” my HTML coding?
Thanks in advance.