What's the error message? I don't see why Galeon would fail to build due to this.

The only reason it would is if some other .la file was compiled with
libaudiofile.la installed, and thus contains a hardcoded reference to 
libaudiofile.la.

Exact! This is my fault.
I previously installed ximian audiofile-devel containing libaudiofile.la,
then I manually built some other GNOME sources, and references to
/usr/lib/libaudiofile.la have been spread in other .la files. Coming
back to redhat audiofile-devel caused the problem to appear.

Decided on a preliminary policy of "no .la files", so closing the bug.
Now we need bugs on all GNOME packages that _do_ have the files. ;-)

The RedHat package "audiofile-0.2.3-3.src.rpm" has a small error in the spec
file that causes libaudiofile.la to not get included in the audiofile-devel
package even though the file is built. The "%files devel" section consists of
the following:

%files devel
%defattr(-, root, root)
%{_bindir}/audiofile-config
%{_libdir}/lib*.so
%{_libdir}/*.a
%{_libdir}/pkgconfig/*.pc
%{_includedir}/*
%{_datadir}/aclocal/*

which does have a line for "%{_libdir}/libaudiofile.a" but not
"%{_libdir}/libaudiofile.la". I have seen this fixed in other spec files by
changing "*.a" to "*a", thus including any file that ends with "a".

I recommend changing "*.a" to "lib*.a", adding "lib*.la", and adding "lib*.so.*"
 so that the library prefix "lib" and suffixes "a", "la", and "so" are obvious
and any files with a version on "so" are included by default. The section would
look something like the following.

%files devel
%defattr(-, root, root)
%{_bindir}/audiofile-config
%{_libdir}/lib*.a
%{_libdir}/lib*.la
%{_libdir}/lib*.so
%{_libdir}/lib*.so.*
%{_libdir}/pkgconfig/*.pc
%{_includedir}/*
%{_datadir}/aclocal/*

I have seen this oversight in the Ximian audiofile packages and analogous
oversights concerning "lib*.la" in other packages from RedHat, Ximian, and
others. Also, many libraries do not have the "lib" prefix on file names,
although it seems to be a useful convention, and would need to exclude it from
globs, using "*.a", "*.la", "*.so", and "*.so.*" instead.

major, the non-inclusion of .la files isn't an error, it's a deliberate policy.