WordPress inserts p tags

I just started converting my xhtml site over to a wordpress theme. So far it’s been good. I turned off the visual editor because I don’t need that so I’m only using the code editor. But I’m having a really big problem with WordPress inserting <p> start and end tags into my codes. No matter what I do it inserts it next to the standard center tags and the div center tags (I don’t have both in there at the same time. I’ve tried both to see if it would stop.) and it just won’t let it go. I’m also have images in there but they’re also supposed to be centered as well. I’ve turned both the fix xhtml function on and off and it still won’t stop inserting the paragraph codes. The paragraph codes are ruining my xhtml 1.0 transitional validation. How can I get wordpress to stop doing this? Again, the visual editor is disabled via my profile.