hey overflow experts- save my marriage!

[iansfishy]

for some reason I can not seem to quiet down my overflow. I either have to have the return pump valved way down or it is incredibly noisy. Ive done four of these now and have never had one this noisy, am i missing something here? At times the level in the overflow will shoot right up to the top of the overflow then quickly back down to its regular, yet noisy spot. This is a new tank, 2-3 days old and its driving me crazy! Anyone got any ideas?