failed tests AC_CHECK_LIB

[Matej Tyc]

Dear friends,
it happened to me multiple times that a test fails when cross compiling
with mingw.

This fails (this is how autoconf makes tests):
//test1.c
char DirectSoundEnumerateW();
int main()
{
        DirectSoundEnumerateW();
        return 0;
}
i486-mingw32-gcc test1.c -ldsound
(Error: /tmp/ccKQdOBh.o:test.c:(.text+0x1e): undefined reference to
`_DirectSoundEnumerateW')

This does not (this is how our source code looks like):
//test2.c
#include <dsound.h>
int main()
{
        DirectSoundEnumerateW(0,0);
        return 0;
}
i486-mingw32-gcc test1.c -ldsound

This example is Wine library, but it happened to me with DevIL image
loading library as well, all pure C libraries.
Any ideas what to do?

Regards,
Matej