The spacewalk began smoothly but at the fag end of the exercise, it had to be extended by an hour as a portion of the metal plate that restrained the feet of Pavel Vinogradov, the Russian commander of the station, was lost as he made his way to the station's American segment on a telescoping Russian crane.More details over here.
Vinogradov was quoted as telling his Russian flight control team as "We have a problem. We have the foot restraint gone. It was in the closed position. We don't understand it. That's bad."
Space Station crew makes six-hour spacewalk to fix problems

Two ISS members undertook a six-hour spacewalk to fix a clogged oxygen generator, replace a faulty video camera and retrieve external science experiments early Friday.