Flash Image request halts server

I have a flash gallery application that preloads a bunch of images. A client went through them, opening and closing quickly, and produced an error I have never seen before.

It seems that closing a browser window between the time that flash requests an image (loadMovie), and the time its displayed causes the domain (not the server, oddly enough) to become unreachable until the user shuts down the browser completely.

Has anyone encountered this error, or an incarnation of it, or have any suggestion as to what I can do, or am doing wrong.

Let me know if you need me to be more specific, or provide examples.

Thanks in advance.