I just installed our software, which was created using gcc 3.3.5 under 6.3.2 onto the new 6.4 alpha.   None of my C++ 
application will run, but I have no issues with regular C program using the same compiler.

Looking at the core dump reveals that the applications are dying while doing a dynamic_cast<> operation.  I'm not sure 
if this is a 6.4 issue or a gcc 3.3.5 issue.

Richard