minor, but annoying

Anyone else have a disappearing coolant problem in their late model 4cyl?The models using the pressurized coolant resevoir (no cap on the radiator) seem to lose coolant as fast as you can add it. The level will never fall below a certain point (multiple oil changes), but if you top it off to the fill line, it'll all be gone (1/2 to 1 gallon) in three thousand miles. Supposedly there's an "engineering issue" at the engine factory. Nothing has been done to help fix the problem though. The dealer could not pinpoint where the coolant was escaping.