To quickly debug, try setting all paths as absolute to make sure you are loading files from where you think you are. If that works, then review your relative paths.
Also, I don't think you want to have normal flash object mark up in your alternative content area. You will be writing your flash content in there anyhow if they have the correct flash player etc. Backup text like supplying a link to download the flash player would be more appropriate.
This also might be why your flash is failing, as you are not specifying and xml file in your object markup version... delete it and try again...