Redirect to new page fails after flash post to server

I have a rails app that embeds a swf. The swf takes user input and posts to the server. For testing purposes, the controller is just redirecting the browser back to another page without processing the data. Interestingly, after the post, the server log and the firebug log shows what clearly looks like a successful redirect (200) showing the correct URL GET, but the browser does not actually move to the new page and is stuck on the same page with the flash app. Same behavior occurs in both Firefox and Safari.

If I cut and paste that URL contained in the log into the address bar, it works properly. So I must be missing something fundamental since all looks like it should be working. Any thoughts?