Thanks Yaobing - I'd agree that most (including myself) prefer quick ch changes and for now the solution is to use AC3Filter which handles the MPEG <-> DD changes just fine - but NOT the default MS or even FFDSHOW (though the customised DVB TV Apps must also cater for this as they work fine). I'm not sure if they still do it, but there was an issue that some of our HD channels used to change their output format pending on what is being broadcast, if so you can not even keep the default values in a field....
Nathan