We had some Libsyn.com problems on Thursday and Friday which have since been resolved.
If you are in iTunes, right click on the top line for our podcast and choose Update. This should refresh from the feed and you should be able to download those podcasts.
If you are using another program, let me know the program and the episodes which are problems.
You can also download an episode directly from here:
http://www.mrexcel.com/podcast/learnexcelpodcast.html
Bill