Really easy fix, for some reason qtcreator/mingw makes redundant .a libs in addition to the .dll's on windows for the dynamic libs.
Compile it as normal and when it comes up with the linker issue, go into where the .dll's were built and delete the redundant .a files, then hit build again. The linker will now use the dll's instead of the empty .a files.
This happened to me when trying to compile Horde3D on windows via Qt/MinGW.
Also first post here, howdy!
The .a files are used to tell the compiler where in the DLL each function is(iirc), so they are not redundant.
