Car in question is a 01 MK4 Golf, with 69k on the clock and have noticed that my second gear whines only when slowing down i.e drop to second gear making sure foot is off gas pedal. The noise would stop if I clutched in, or eventually on it's own once it has reached it's natural idle and continues to drive along. It does this regardless of whether it is warmed or not. It does not however whine when accelerating on any of the gears, is this serious? Has anyone else had this problem?

(gearbox is standard I have not changed it)

Thanks in advance!