What rankles with me is when people sing "For the sake of Auld Lang Syne". I don't think 'sake' appears in the original words. Syne is a corruption of 'since' in Lowland Scots, so I agree that the 's' should be devoiced. I must have sung Auld Lang Syne dozens of times during my many years in Edinburgh and Glasgow, and also in Fife. By midnight everyone is at least mildly sozzled, so maybe we weren't pronouncing it all correctly! Do you remember the Queen gingerly holding Tony Blair's hand (but refusing to cross arms with him!) at the Millennium? She looked about as happy as a starched fart!