A bit of a side-track from the actual issue, but it's possible to save files in windows with unix newlines (and vice verca), so this isn't really a good indication of where the files orignally came from.

But to the issue at hand.. I agree, I don't think files should be executable unless they need to be. One reason this might have happened is that if you have multiple authors working on a project using CVS, and one or more of them are running Windows, you often get files that are set to 755 checked into CVS. Once in CVS, you can't (easily) change the permissions, so everytime they're checked out, you have to manually change them.