Deactive code interpretation

Is there any way to disable any code modification that occurs at runtime.

I explain: I modify some post’s html code directly in the database because I want a very specific layout. The code in the database looks perfect. But as soon as I load the post in my browser I see some new tags that I never wrote and that are still not in the database entry. For example I get some new <p></p> and some
and that of course destroy my layout.

Any advise would be more than welcome.

PS it seems that I didn’t have such a problem with the version 2.0.7.

CU Jerome