The Internet major said the corrected vote tally showed that nearly 34 per cent of votes cast were withheld against Yang, more than double the originally reported figure of 15 per cent. About 40 per cent of votes were withheld from Chairman Roy Bostock - nearly twice the figure previously reported.
The error does not change the outcome of the election, but it does reflect a high level of shareholder frustration with Yahoo management over its handling of a now-withdrawn $47.5 billion takeover bid from Microsoft Corp.
This shareholder revolt could see a stronger call for Yang to step down. His disapproval has now dropped down to the range that former CEO Terry Semel experienced during the last year's annual board meeting, days before he lost his job.
The problem was caused by a tabulation error by Broadridge Financial Solutions, which was representing Capital Research and Management Co -- Yahoo's largest shareholder.
"In essence, it was a truncation error in the final printout," the processing services firm's Senior VP Regulatory Affairs Chuck Callan said, adding that "the problem was identified and fixed...the error did not change the outcome."
Capital and its sister concern Capital World Investors, which together control roughly 16 per cent of Yahoo's stock, had advised its funds to withhold votes for the re-election of Yang to the board of directors.
In addition to Yang and Bostock, the revision added a large number of "no votes", against three other Yahoo directors.
The vote against supermarket magnate Ron Burkle jumped from 18.8 per cent to 37.9 per cent. Votes against Arthur Kern jumped from 22.1 per cent to 31.7 per cent while votes against Gary Wilson went from 18.2 per cent to 27.7 per cent.
No mistakes were detected in the votes for Yahoo's four other incumbent directors Eric Hippeau, Vyomesh Joshi, Mary Agnes Wilderotter and Robert Kotick.