As far as we can tell, some versions of gcc don't support these types. We believe there are some severe bugs in the implementation of exceptions for some gcc compilers.
Exceptions require some interaction between compiler, assembler, and runtime libraries.
We're not sure exactly what is at fault, but one failing combination is gcc 2.7.2.3 running on SuSE Linux 6.0. The problem on this system can be seen with a rather simple test case of an exception thrown from a shared library and caught in the main program. A variation of this problem seems to occur on AIX, although we believe it does not necessarily involve shared libraries on that platform. If you see a trap that occurs when an exception might be thrown by the Berkeley DB runtime, we suggest that you use static libraries instead of shared libraries. See the documentation for configuration.