Problem using MinGW to compile extension module

[Greg Ewing (using news.cis.dfn.de)]

I'm trying to use MingGW32 to compile a Python extension module that
links with the Firebird relational database system.

I've used pexports/dlltool to create a libgds32_ms.a file containing
definitions for linking with gds32.dll, the Firebird interface
library.

All goes well until the linking, when I get

Info: resolving _isc_start_transaction by linking to 
__imp__isc_start_transaction (auto-import)
fu000001.o(.idata$3+0xc): undefined reference to `libgds32_ms_a_iname'
nmth000000.o(.idata$4+0x0): undefined reference to `_nm__isc_start_transaction'
error: command 'gcc' failed with exit status 1

I can't even tell where _nm__isc_start_transaction is coming
from -- there doesn't seem to be any symbol at all containing
the letters "nm" in either libgds32_ms.a or the .o that I'm trying
to link.

Python version is 2.3.3.

Does anyone have any idea what's going on here?

-- 
Greg Ewing, Computer Science Dept,
University of Canterbury,	
Christchurch, New Zealand
http://www.cosc.canterbury.ac.nz/~greg