Sound probs in mingw build (but not visual studio!)

I was trying out kobo deluxe on winxp sp2 (nice game) - but unfortunately
the sound was crackley (comes with SDL.dll 1.2.3, pretty old, fair enuf).
I’d noticed in the past that mingw (=cygwin) builds had sound probs, no
idea why, and dropped in a VS compiled SDL.dll 1.2.11. Perfect sound.
I recompiled 1.2.11 under cygwin and dropped that in with the result that
the sound is not crackley, but incredibly quiet (but still crackley in my apps,
perhaps my buffer size is inopportune). In any case, the two builds
should have the same sound properties, right?

P.S. The mingw SDL.dll doesn’t have a version number!