"Undefined Reference to (method name)" When Accessing a Method in a Static Library

I’ve been trying for more than one month to access a method found in a library called libcocosnas_static.a
I’m using Cocos2d-X version 2.0.4. The library has been used many times by my company to make games using cocos2d-1.0.1-x-0.12.0 without any problem.
This is what I’ve done:
1- I added the include paths of the library to both eclipse and Android.mk
2- Included the .h file using #include “NASPlatformUtil.h”
3- Added the libcocosnas_static.a file to the proj.android\obj\local\armeabi folder
4- Added “LOCAL_WHOLE_STATIC_LIBRARIES += cocosnas_static” to the Android.mk file
5- Called the function using: NASPlatformUtil::openUrl(“http://xxx.xxx.com/”);

I can right click on the function, click Open Declaration and get it without any problem, but the compiler keeps on giving me that dreaded error
Hope you can help me with this

Thank you in advance