Fighting their affiliates has already lost them some sympathy points, now the networks are contending with Jerry's Kids. The Muscular Dystrophy Association, like the affiliates, is fighting the networks' bid to lift the audience-reach cap from 35% of U.S. households. MDA officials say letting the networks buy more stations would be "catastrophic" to their annual Labor Day Telethon, which supplies the bulk of the organization's funds. Virtually no O & Os air the telethon because they don't want to pre-empt network programming and more stations will drop the show if the nets are allowed to add more outlets, MDA says. MDA's regional organizations, beginning in August, have been asking Congress to oppose a cap increase and several of the groups' letters to the Hill recently were forwarded to the FCC, which has asked for comment on raising the limit.