The bill acceptor in the WS 2 started acting up recently, it'll take the cash and won't give credit it is happening on the $5 and $10 bills. A customer today selected the $9 wash, WS2 displayed the add $9, he added a $10 bill and the WS2 kept displaying add $9, so no credit for the $10 the customer inserted, the customer then added $5 bill and four $1 bills and got his wash. In the last month I had 5 customer describing the same problem. Any ideas? Does it sound like a validator?