Windows上有很多“不兼容的签名”错误，但在使用Flex 4 Gumbo的Mac OS X上却没有

I have a pure Action Script 3 project which I am compiling with the Flex 4 SDK. I have a standard Makefile which automatically invokes compc, mxmlc, and asdoc as appropriate. The project is compiling cleanly with no errors or warnings on my Mac OS X 10.4+ computer; however, when sharing it with a coworker developing on Windows XP (with Cygwin installed), he gets a very large list of "incompatible signature" errors. Why is he getting those errors? The signatures don't appear to be incompatible.I have a pure Action Script 3 project which I a