Is this right?

[NotAGolf]

I'm trying to do some matrix multiplication on 8x8 matrices in c++. I found this code to do it:

for( int j = 0; j < 8; j++ ) 
      for( int i = 0; i < 8; i++ )
	    for( int k = 0; k < 8; k++ )
	          C[i][j] += A[k][j] * B[i][k];

I'm getting frustrated because my program is working in parts and not in others (mainly where 0's and negative numbers are involved I think). Does this code look ok or is there something wrong?

Thanks.