Islanders are warned of a telephone scam that promises to clean up your computer, but in fact does nothing except clean out your credit card.The Observer received a call from a Skidegate resident on Wednesday, saying he had lost $1,800 Tuesday to the scammers night.He says his computer is now useless because the scammers changed the password, and his credit card was drained, although he expects to get the money back."These guys are pretty cagey," he said, "they are quite persistent, they kept me on the phone for hours."Islanders are advised to be very cautious, even suspicious of anyone claiming to be able to fix a computer over the phone, especially when they start asking for payment.