I have a customer who bought my tn-250 compatible and put it in their fax machine and now it is giving them trouble. This is only the second cartridge this fax has had ever, and it was printing fine until it ran out and then we changed it twice with different compatables and it leaves a haze down the first page and then almost solid black with the second page. Anybody have much experience with this toner/printer/drum or any idea what the problem might be?