big debts from big buyers........they buy big and pay regular, you trade with them for a while and take it for granted, then all of the sudden they dont pay 1 month, you think aaaaaah its cool, they always pay its just a glitch, you ring, they make promises, blame the accounts chick, you still need their business they are a big customer, 60days hits and still no pay they are another month into you and you suddenly realise you have been screwed and its too late