bug fixing for a program which uses OpenCV library

I am using cvStartReadChainPoints() to read the contour points in function sSign::shape_signature(const char *filename). I have encountered 2 weird bug of it. If I comment out the lines of cvStartReadChainPoints((CvChain *)contour, reader); and cvReadChainPoint(reader); The weird problems disapear. 1. If I call the function sSign::shape_signature(const char *filename) which contains lines of cvStartReadChainPoints() from main(); it works fine. If I call it from main(), enter anotherFunction(), then call sSign::shape_signature(const char *filename). What I get on consle is a bunch of something look like this - "20349: binding file /usr/lib/libstdc++.so.6 to /usr/lib/libstdc++.so.6: normal symbol `_ZNSt13basic_ostreamIwSt11char_traitsIwEE5flushEv' [GLIBCXX_3.4] Segmentation fault" That means, I can only use cvStartReadChainPoints() in the function which is no more than 2 layers of function calls. 2. I have changed my code, sSign::shape_signature(const char *filename) remains the same. I call this function in main() as follows: main(int argc, char* argv[]) { shapeSign.shape_signature(argv[2]); cout<<argv[3]<<endl; shapeSign2.shape_signature(argv[3]); } This is the most weird thing I have ever met. cout<<argv[3]<<endl; prints nothing on my console. That means the memory was tempered while calling cvStartReadChainPoints(). I need someone helps me workaround this problem. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. ## Platform I am coding it on Linux with GCC and Anjuta IDE. Actually you may do it on any platform.