On July 20, I was able to receive an MMS from my brother-in-law. He's on an iPhone w/AT&T, I'm on T-Mobile USA. On July 31, he sent me two MMS's that I can't retrieve (message says "Downloading MMS" for about 5 seconds and then nothing happens), though on the same day (w/same fMMS version), I had no problem receiving one from my wife who's on Verizon. Not sure what fMMS version I had installed on July 20 though I think I've updated the version at least a couple of times since then. As of July 31, I had 1.2.2 installed.

Any clues?