Today I learned the hard way that that when you read values from the fft array i.e.

double value = fft.read(1,5);

you CANNOT come back and execute

double val = fft.read(3,7);

The values you read earlier have been "used" and will come back as '0'; If you need the values in multiple places in your program, you better read and save the values in temp variables. That behavior cost me half a day until I realized what was going on.

Just thought someone else might have similar issues where a program behaves unexpected at times.