I bought a few months ago a re-manufactured black ink cartridge ( hp21 ), I used it all up and then refiled it with ink ( I've done this many times, I know how to do it ) , and when I put it back in the printer ( HP F2280 AIO ) and the black cartridge light started blinking and the software for the printer announced me that theirs a problem with the cartridge. I figured that the cartridge might be dry, so I put it in some warm water and ink started poring out so that isn't the problem. The expiration date on the cartridge is 2011/05/12 so it's not expired. If anyone can give me some advice, other than to buy another cartridge I would appreciate it.