debugging causing exceptions?

i removing bad information an concentration i writting controlling c++ visible studio 2k3 i solid debug it. following i found throwing an difference nonetheless i can't lane down.

then i placed try/catch blocks low behold, i don't debug there exception. is, i have formula looks this:

std::vector<myclass*> listofstuff;
.
.
.
try
{
.
.
.
   const myclass * localpointer = listofstuff[i]; //this where difference occurs
.
.
}
 locate (...)
{
   int x = 0;  //place smack here
}

so i step by formula line line i'll an difference shot catch. nonetheless i only let run breakpoint inside locate zero happens. controlling an iterator same behavior. i successfully check distance settlement i know i'm within bounds.


can anyone tell me what's going on? matters i'm controlling customary windows libraries opengl.