Compaq Computer Corp, which reiterated that it was heavily backlogged on its new budget Prolinea personal computers last week, said on Friday that it expects to clear the backlog by the end of August, but distributors are sceptical and say it may be September or even October – and see the company losing sales to competitors in the meantime: Compaq has had to add one shift in Scotland and two in Houston so that both plants are now running three.