For those saying it's easy to go from iOS 5 beta4 back to iOS4 could you please explain how you're doing it?
I've reinstalled the current iTunes, putting in both recovery/DFU mode both of which fail the restore.
I've also tried a bunch of other methods which haven't been successful.
As far as I am aware, I thought you just had to reinstall the latest stable version of iTunes, put your iPhone into DFU mode (Which isn't the same as recovery mode), hold alt and click restore and select the latest iOS 4 release.