The cherished dinner hour void of telemarketers could vanish next year for millions of people when phone numbers begin dropping off the national Do Not Call list. The Federal Trade Commission, which oversees the list, says there is a simple fix. But some lawmakers think it is a hassle to expect people to re-register their phone numbers every five years. Numbers placed on the registry, begun in June 2003, are valid for five years. For the millions of people who signed onto the list in its early days, their numbers will automatically drop off beginning next June if they do...