Hi Joe,
I never did fully resolve it in Flex, mainly because I was able to get the site to display, and it only notifies you when debugging mode is on. In another development environment, I would say that an en_US resources folder would have to be added to the project and built in to the project. Since I am not deploying the site internationally, I left it alone.
The problem that was preventing the site from running appeared tied to taking widgets designed to work in the version 1.3 into a 3.0 environment. Without changing the coding, 3.1 and then 3.2 were released, and the modifications I made to the custom widget started to work. I had thought it was failing to run because of the missing components, but I no longer believe that was the case. Since the release of 3.2, I have had no problems at all with custom widgets or in updating our FLEX sites.
Corey