JNI crash during info- getHWND()

Question

It appaers that the JNIENV * and/or jobject are invalid and when the function getHWND() [which returns a JAWT_Win32DrawingSurfaceInfo*] is called it crashes. Can anyone see something obvious why this fails I've written other projects using the mechanism, but only this one fails.
Thanks
David
//Java code
public class CommFeedback extends Canvas
     public String nativeLibraryDirectory;
     public String nameOfDllBeingUsed;     
     public String memInfo;
     public String cpuInfo;
     public String graphicsInfo;
     public CommFeedback()
          this.nativeLibraryDirectory = System.getProperty("java.library.path") + "\\";
//          System.out.println("Native Library Directory : " + nativeLibraryDirectory);
          loadDLL();          
     public void GetInfo()
          cpuInfo = getCPUInfo();
          memInfo = getMemInfo();
          if( initOpenGL() )
               graphicsInfo = getGraphicsInfo();
               System.out.println("Graphics Information");
               System.out.println(graphicsInfo);
     public void printInfo()
          System.out.println("CPU Information");
          System.out.println(cpuInfo);
          System.out.println("Memory Information");
          System.out.println(memInfo);          
          System.out.println("Graphics Information");
          System.out.println(graphicsInfo);
     private void loadDLL()
          String nameDLL = "Comm";
          try
               System.loadLibrary(nameDLL);
          catch(Exception e)
               e.printStackTrace();
     public native String getCPUInfo();
     public native String getMemInfo();     
     public native String getGraphicsInfo();
     public native boolean initOpenGL();
//C++ code
     class JAWT_Info * info = NULL;
     info = new JAWT_Info(env, panel);
     std::cout << "Before info->getHWND()" << std::endl;
     if(info->getHWND() == NULL)
          std::cout << "info->getHWND() == NULL" << std::endl;
          return 0;
     }

Answer 1

I've added a check to determine if info has a value of NULL and info contains a non NULL value. I assumed that the values for the JNIENV * and/or jobject are invalid because the the dsi is derived from this information.
     class JAWT_Info * info = NULL;
     info = new JAWT_Info(env, panel);
     if(info == NULL)
          std::cout << "info == NULL" << std::endl;
          return 0;
     std::cout << "Before info->getHWND()" << std::endl;
     if(info->getHWND() == NULL)
          std::cout << "info->getHWND() == NULL" << std::endl;
          return 0;
     }typedef struct jawt_Win32DrawingSurfaceInfo {
/* Native window, DDB, or DIB handle */
union {
HWND hwnd;
HBITMAP hbitmap;
void* pbits;
* This HDC should always be used instead of the HDC returned from
* BeginPaint() or any calls to GetDC().
HDC hdc;
HPALETTE hpalette;
} JAWT_Win32DrawingSurfaceInfo;
JAWT_Win32DrawingSurfaceInfo* dsi_win;
HWND getHWND()
if(dsi_win == NULL)
return NULL;
return dsi_win->hwnd;