Here's the gear: Mac iBook 1.33 Ghz laptop with 1.25 gb RAM, running OS X 10.3.9. Presonus Firebox with Cubase Le Ve 1.0.7. the quick rundown: I plugged a guitar in, recorded about 2 minutes of audio, sounds fine. Then I inserted a drum loop and repeated it to the same amount of time. Sounds fine. Then I inserted reverb on the drums, and some overdrive on the guitar. It starts to crackle and pop a little. I play back the audio again and within about two or three minutes, there is more crackle and pop than there is audio. Presonus' website is about as helpful as glasses on a bat. There is NOTHING for information. My blue sync light is on. I try changing buffer and the sound is still a mess. Did I do something wrong or is there a setting I am overlooking? Help!