almost every one of those we've sold has come back and the customer upgraded to a better amp, with only a few exceptions. for mids/highs they aren't bad for a cheap amp. but for running subs, you can do a whole lot better for just a little bit more money. the alpine mrp-m350 is a ballsy little amp, and is very cheap. great for subs on a budget.
but for your situation, turn the gains down. you can overdrive the input on those amps very easily, they don't like a lot of voltage. and if you are using the high level inputs, ditch 'em. they're nothing but problems, on those amps the high level inputs absolutely ****. real loose and shady connections on the cheesy little plugs they give you and we've talked with clarion about the issue, but have yet to see any changes.