Something is up at Tagworld, the social network site described as the next-generation Myspace. Fred Krueger and Evan Rifkin, the LA internet company's founders, have not logged into their own service in about a month. The company's management page has been taken down. Tagworld staff are telling callers that both founders are "out of town" at the moment. The company was backed, as recently as last February, by Tim Draper, the famously scattergun Silicon Valley venture capitalist and amateur rock star. Draper Fisher Jurvetson invested $7.5m. But Tagworld never made inroads into Myspace's audience; its reach appeared to peak about the same time as the company raised money. The problems at Tagworld serve as a reminder: in the competition between social network sites, it's winner takes all. And there are few winners.