Can BP blogs on free version (non-supporter) post ads in sidebar?

I have a BP site that offers a free and premium option. I'm running ads on the blog posts from free users (non-supporter), but I wanted to allow them to post their own ads in their sidebar. But when I test this on a free site Adsense and graphic codes disappear when I hit save on the Text widget. The only way to add a graphic ad code in a post is to use the Add Photo option and then add the link as opposed to pasting the code in the content area. Is this something that support regulates? And how would I make it so free users can use this type of code?