Over 6% of Vodafone shareholders voted against the re-election of the phone giant's chairman at the company's annual meeting today.Around 6.5% voted against Sir John Bond, based on proxy votes, while 5.9% voted against the re-election of his deputy, John Buchanan.The protest vote was led by the Ontario Teachers' Pension Plan (OTPP), which holds 0.4% of the firm and has been calling for a board shake-up."For at least the last five years, the company has had significant structural and strategic weaknesses, resulting in Vodafone trading at a substantial, persistent discount to its asset value," the OTPP said.