A last-minute move to avert a potentially bruising strike that could cost more than 27,000 workers weeks of pay would usually be met with unalloyed relief. Not with the Machinists union faithful Wednesday night after Boeing Co. aircraft assembly workers voted overwhelmingly to strike for an unprecedented second time in three years, then learned both sides had agreed to a 48-hour contract extension at the request of Washington Gov. Chris Gregoire and federal mediators. Chief negotiator Mark Blondin and Tom Wroblewski, president of Machinists District Lodge 751, were repeatedly shouted down at the union hall with catcalls of "Sellout!" and "What was the strike vote for?" For Boeing, the rejected offer took "the best contact in the industry and we made it better," Vice President of Human Resources Doug Kight said in a news conference. He repeatedly turned aside questions of whether Boeing was relieved to get another chance to avert a strike by offering a sweeter deal. "Responding to a request from the federal mediators is appropriate for both sides," Kight said. "My job at this point is to listen to the union." Jim Proulx, a Boeing spokesman, said company and union negotiators would meet together with a federal mediator at an undisclosed time and location Thursday. Boeing's "best and final offer," presented last Thursday after talks that began May 8, included bonuses totaling at least $5,000 and averaging $6,400, raises averaging 11 p ...