Usually I am satisfied with purchases from you. But in this one instance - I bought a black cartridge from the DX 4800 printer range earlier this month - I wasn't. Because my previous black ink hadn't expired till today, I hadn't replied to this review request yet. When I fitted the new cartridge, the printer went into error mode, and when I tried to print a document in 'text' mode, only the pink parts of the document showed. Then I tried a different document on 'draft' mode; it printed the whole document only in pale pink! I then re-shook the cartridge (as one is supposed to do, according to the printer manufacturer's advice); black spots of ink went everywhere. Thus I suspect there is a leak or some other malfunction in the cartridge. Please advise.