NSight local debugger connnect and disconnected immediately

Just installed VS2008, CUDA 5 and NSight 3.0 on my computer with Windows 7 OS and Tesla C2075 GPU. I tried to set localhost in the launch option which is required by local debugging and disabled secure connection because this is only local debugger (tried to enable it too but it did not work either), as described here:
http://http.developer.nvidia.com/NsightVisualStudio/3.0/Documentation/UserGuide/HTML/Nsight_Visual_Studio_Edition_User_Guide.htm

But whenever I clicked “start CUDA debugging” the program exits and on the right corner of the screen it shows “NSight Connected xxx to xxx” and then immediately shows “NSight Disconnected xxx from xxx”.
I searched the forum and tried to use google. I can find some posts with similar problem but none was properly resolved.
Anybody knows?