incorrect and negative quantities after stock take

hi all

my client dd a stock take ad after the stock take the in whse quantities are incorrect and negative.

what the system does is it takes counted nd lesses the difference and gives a wrong and negative amount.

e.g. item glw4: he counted 4 in the warehoue and the difference was 16 and now theres -4 in the warehouse.

they are on 2007 PL47.

Please assist