Red faces have replaced the golden masks at the British Academy of Film and Television Arts after voting for its prestigious Bafta awards had to be suspended.

It followed the discovery of major errors in the polling process. Not only did the list of nominees omit the names of several well-known actors, in at least one case a star's gender had been swapped, with an actor nominated for best actress.

Officials were forced to close the online voting site last week after being told that actor Ray Winstone was missing from the cast list forCold Mountain.

The academy had been alerted by the film company, Buena Vista, which had been contacted by an academy member asking why the actor's name was absent.

Further errors were then spotted and an email was circulated to all 4,000 academy members on Friday night outlining 24 additions and corrections to the nominee lists they had already received. Polling resumed on Saturday morning.

Apart from the absence of Winstone, other omissions included that of Andy Serkis and John Rhys-Davies - who play Gollum and Gimli - from the roster of actors in The Return of the King, Cuba Gooding Jr from The Fighting Temptations and Hope Davis from American Splendor. Philip Seymour Hoffman was also missing from Cold Mountain.

The actor Stéphane Rousseau was listed in the best actress category for The Barbarian Invasions. In other films, Bafta mixed up the categories for original and adapted screenplays.

The academy has beefed up its film awards, on 15 February, to the point where they are now considered second in importance to the Oscars, which they precede by two weeks.

Bafta said that the problems had been due to a combination of human error at the academy, compounded by the fact that some film companies had supplied only partial lists of actors. Amanda Berry, its chief executive, said that less than 1 per cent of academy members had voted and that they had all been given the opportunity to change their votes.

Normally, the academy compiles the lists of up to 40 actors and actresses from each film. But since the ceremony is a week early this year, Bafta had to speed up the three-stage voting system and relied upon film companies to supply names.

¿ An all-singing instalment of the cult television series Buffy the Vampire Slayer has gatecrashed a shortlist of the greatest musical films. In the show, Buffy does battle with a music-making demon, prompting the entire cast to burst into song.

The episode, "Once More With Feeling", is the only small screen offering to make it into the top 20 favourite musicals of Channel 4 viewers.