RedHat 7 ships with GCC version 2.96. After experiencing compatability issues with this software, some research and contacts uncovered the fact that GCC v2.96 is a beta version of the new and upcoming GCC v3 and was never intended to be released as a development suite and is not forward or backward compatable with previous or upcoming versions. Check out http://gcc.gnu.org/gcc-2.96.html for more information Why was Redhat 7, touted as a development platform, shipped with a never meant to be released version of the C compiler?
If you encounter any bugs, please file them here, but the fact that we have released this compiler is not a bug, it was intentional, see Richard Henderson's explanation in lwn.net archives for why we decided to ship this. If you talk about C++ binary compatibility, then no g++ so far has been compatible with other major g++ version (2.7.x vs. 2.91 vs 2.95.x etc.). C should be binary compatible on ia32 (maybe with exceptions of -mregparm in some cases).