invalid lib problem when compiling with CB+gcc

I have successfully compiled OgreBullet using the Code::Blocks project files, but when I link the lib files to my porject i get an error saying that the file format is invalid. I have carefully rebuilt Bullet 2.74, OgreBullet, my project, everything, but nothing works. Any idea about how to solve this?

I solved the problem by changing the lib name in the project properties. I removed _SDK and also the extrension .a, it is generated automatically anyway.