Error: L6218E: Undefined symbol cvWaitKey (referred from main.o)

Hi everybody, i am trying to use the OpenCv's libraries with keil and i ve done this:
1. Added a Group called libs where i ve put al the .libs files
2. In the project configuration added all the necesary include paths ( and even more just in case ). libraries, sources, and .h paths

I have created a simple project, which compiles and works perfect without using Opencv libs

But when i try to use this libs i get this error:

Error: L6218E: Undefined symbol cvWaitKey (referred from main.o).

(CvWaitkey is defined in highgui.h which is included at the top of the main file)

It seems preety obvious that the compiler doesnt know where is defined cvWaitKey but i dont know what i am doing wrong because i ve ensured to include the highgui.h in the main file and added the include path in the project configuration.

Any idea?

Thanks!

here u have a print screen:
www.mediafire.com/.../8c7v7kmakvi2f5mfg.jpg