Garageband with Zoom G2.1u - WEIRD buzz problem

Hi,
I just got a new macbook so I'm a real newbie.
I'm plugging my guitar into my g2.1u which goes into my computer via USB.
When I record with GarageBand the first minute or so is perfectly fine but the next minute it makes a really noisy, fuzzy sound (I think it has delay on it also). It just kicks in randomly.

Please help me. Would it be a problem with my MacBook? Could I fix it?

Thanks,
Henry

bump - PLEASE help me!!?

hey

i had the same problem!!!! the noise is due to invalid patch settings on your zoom for recording!!!In your destined patch the cabinet settings must be changed to "Et" not "Cb"!!! hope this helps