I was hoping you'd had success resolving the problem. The tech support is a freaking joke. Today they e-mailed me and had this to say:
"Some of our customers have experienced this same error. This error usually happens when the movies that you are trying to remove are in process of being allocated instead of displaying the message "This is being shipped to you and cannot be removed", Error 500 page is displayed."
Morons. I have 904 movies in my queue, so I guess I'll wait until it gets below 900 and see if it helps. But I've had it up to the max of 999 where I couldn't add any more and I easily removed ones I decided I didn't want to see.
Incidentally, from the queue management page there's a link called Privacy Settings. I went to that page and there's a button to make all your movies private or make them all public. I get the same error message if I click that button, but I can set them to private or public one at a time.
I'm pretty sure they have a programming error. I think they're ASP scripts that are run on their servers and I think they've messed them up. But I think it is only impacting a few people otherwise there would be a larger outcry. Maybe it's only a problem for people with a lot of movies in their queue.