The delays had been expected as a result of the strike
Boeing has delayed the first flight of its 787 Dreamliner aircraft until 2009, having previously aimed to get it off the ground before the end of 2008.
It is the fifth substantial delay to the Dreamliner's first flight, which was originally planned for summer 2007.
Boeing has blamed the delay on a 58-day machinists' strike, which finally ended on Sunday.
It also blamed a problem with the installation of the fasteners that hold the aircraft together.
A company spokesman said that inspections had found that about 3% of the fasteners on the four test jets had been incorrectly installed by suppliers, being either too far apart or too close together.
Two years late
A new launch timetable will be announced once the problems have been fully assessed.
The project has been plagued by delays due to problems with suppliers and shortages of parts.
Some airlines have been told they will have to wait two years longer for their aircraft than had originally been promised.
The Dreamliner is a key plank of Boeing's strategy and is the first airliner to be made from a mixture of carbon fibre and plastic.
The materials make it lighter and more fuel-efficient than other aircraft, and allows it to travel further without refuelling.