This is really a weird bug to me and it took me long time to figure out what's happening. To simplify things and reproduce, just create a empty win32 console application using VS2005 and use this code in the main method: 

float a = 411.00418f;
float b = 1.0f;
float c = 0.076279849f;
unsigned short result = (unsigned short)( (a-b)/c );
unsigned short result2 = (unsigned short)( (float)((a-b)/c) );
// Debug: 5374, 5375
// Release: 5374, 5374
printf("%d, %d\n", result, result2);

Why result2 shows different value in debug/release mode?

c++ c visual-c++ floating-point
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