Just a quick bugreport&solve:
in mfile.c so it will compile under windows.
I've added support for *only* writing to memory (and NOT creating the additional file, since you do not need it for only memory->memory operations) which you can get here:
This was done for part of the physics abstraction layer project:
and will be distributed as part of it in the future, thanks for making the mfile publicly available under the BSD license.