Right I'm getting somewhere now.....
I also found another problem, DivX quant pass on non-english system..... XviD was unaffected but DivX would not except the 2,5, 3,5, 4,5 e.t.c and treat it as 2, 3, 4 e.t.c so all previous versions on non english systems would have been incorrect.
I should change my locale and test more often