extensions: creation of .sql files

This is what I did to get PGXS on Windows XP:
- built pg 9.0 from source using MinGW/MSYS
- also installed binary version of pg 9.0
- copied the PGXS tree from source into the corresponding path on
the binary install

Note: I had to use the binary install since the AV software on my
computer didn't allow me to start the server from the source build

To install the extension:
- I ran a "make install" for the unpacked tarball

Problem:
After listing a host of errors from the "period.c" file (new data type
extension), the last line was "make: *** [period.o] Error 1"
It still created a "period.sql" file, but apparently not a functional
one since a subsequent "\i period.sql" command failed...

Any thoughts as to how to diagnose or what could be going wrong?

Thanks,
John