My names Aaron, and I am new to the MinGW Developers list.
I am planning on trying to get Danny Smiths MinGW GCC 4.2.1 Port working on Vista.
If anyone else is interested in this, is working on this and/or has any information that would be useful to this then please would you introduce your self.
AFAICT there is either a memory leak or a runtime system incompatibility/ies or both introduced by Vista.
GCC 3.4.5 on compiling Danny's MinGW gcc-4.2.1 grinds to a hault taking hours to compile some of the gen*.c programs. 
As the FSF say, "Bad Vista" !