FFT Megacore Problem

Hi, I am working on implementing the FFT megacore in my project and I am seeing a couple problems. Here is the info on my FFT:

Variable Streaming Architecture

Fixed Point

Natural Order for both Input and Output

Quad Output Engine

Transform Length of 4096

Data Precision of 12 bits

Twiddle Precision of 12 bits

Targeting the Cyclone II

Here are my questions/issues:

1) I send the FFT the SOP signal and then 4096 clock cycles later (4096 because that is my transform length) I send it the EOP signal. Randomly I am getting all the error messages (01 - Missing SOP, 10 - Missing EOP, and 11 - Unexpected EOP). So my question is, what am I doing wrong? Does the clock sample at rising edge or falling edge? Is the SOP and EOP valid on the rising edge or falling edge? Am I correct in separating the SOP and EOP by 4096 clock cycles?

2) I have a data precision of 12 bits so I input 12 bits real and 12 bits imaginary. On the output I get 27 bits real and 27 bits imaginary. I believe that I get so many bits because of the scaling factor, is that correct? How can I determine which bits of those are the valid bits?

Thank you for any insight you can provide!