Hmmm, I would consider myself an expert here, but I had problems like that recently. I knew my brakes were having issues, and was going to replace them, but when I took a right turn, this high pitched squeal or scraping noise would occur. Sometimes it would occur when turning left, but mainly turning right. The problem was the rotors were completely worn and needed to be replaced, and i'm sure the fact that the brakes were dragging (something wasn't properly lubricated in the calipers) didn't help it at all.
I wouldn't say thats what your problem is, and i'm sure someone more knowledgeable will chime in, but thats what my problem was and my solution so I just thought i'd toss that out there for ya, just in case it helps.
