I'm having a little problem..

After installing, un-installing various scripts, etc - there are some files left on my website. Whenever I delete them, they just come back in a second. there aren't any special characters in the file names, so I'm pretty sure it's not letting me delete theme because they have wrong permissions or something.

Any help?

That probably means another script is regenerating them. E.g: When you delete the MyBB settings file, its regenerated.

I had this happen to me before, its quite something to bring up to your Host, sometimes your host cant do anything about it, however I might have a solution.

Create a similar type of file and overnight it, then delete that file, if that doesn't work, then I also suggest trying to find a "Uninstall script."