I had an issue with the shortcode until I realized that the album wasn't really published.
The wording is a LITTLE confusing. In the status column the button should say "unpublished".
Also, make sure to clear cache.
VERY nice mod - I'm enjoying it as I use it more and more today. Something you could add to your instructions is how to make the "buckets" public for s3 newbies like myself.
Basically: http://ariejan.net/2010/12/24/public-readable-amazon-s3-bucket-policy/ you put that JSON into the "bucket policy". You can find the bucket policy link by looking at the properties of the bucket.