I branched mingw32-gtk2 from windows:mingw:win32, and it builds fine on openSUSE Factor, but it fails on openSUSE_11.2 i586.
The gtk dependencies are identical (linked), and the gtk2 package is practically identical. The build logs are very similar.
Build log: original package succeeds
Both build logs have the identical errors from autoreconf, but on my build, the build stops
autoreconf: automake failed with exit status: 1
error: Bad exit status from /var/tmp/rpm-tmp.Oe3G16 (%build)