I've been wrestling with a perplexing bug for the last several days. But, I seem to have fixed it. Turns out that the main .esp file was somehow corrupt. After rebuilding the entire thing, the bug was gone! Not really an easy thing to deduce to when it could be 1000 other things.
Anyway, I should be able to post a new build [this weekend]. There is a "fun" bug (fun bugs are part of new features in areas of code that are easier to work with) that I had been working on before this nightmarish one showed up. Just need to finish that and will post.