Thanks for the input on hosting files at another site other than the regular webhost.
I will consider that for the future. As of now I am brand new and it is unlikely to be much of a problem. :-)
I know that isn't the problem here though, because I can log onto my site and play all 4 of my current podcasts there. They are also broadcasting fine through iTunes (the feed based directly on my site, not blubrry) and other feed readers. I've tested.
For some reason only on Blubrry do these specific two files not play.
Any other suggestions?
--UPDATE-- (Feb 12, 2012 12:54am CST) -- Well, all 4 files are working now. I don't know what changed but they are all working now.