I updated Flex Builder 3 to the GA version and updated AIR to 1.0. I imported the old project. It picked up my Subversion settings and what not, very nice. I did a new "export release version" and it worked just fine. I tried to execute the .air file and it bombed. It told me that my AIR file was damaged.
WTF!? I tried to run the app directly from Flex Builder. It did nothing. No errors, just nothing. So I tried debugging. Then I finally got an error message about using the wrong version of AIR. I opened up the JsonView-app.xml. There was no "setting" in here for AIR version, but then I saw this
Yep the .M6 was killing me. I removed it from the XML namespace declaration, and voila! Everything worked perfectly. Show your appreciation for my pain by downloading JsonViewer.