Classic great Bordeaux behaviour (shut down between years 4 to 10), but unusual in shiraz, even of Grange quality. But the more likely cause is improper transport and excessive vibration (or rather, opening the bottle too soon after such transport -- it needs 6 months to settle down). Was there a pronounced metallic aftertaste (almost like touching your tongue to a battery)? If so, the lack of rest after too much vibration is the problem. Surprising as you sig says Sydney. But then, great Grange is mostly found in MEL (and the bluestone cellars in that city). FT relevance: transporting this wine by air, such as QF SYD-LAX, does indeed make it undrinkable for months. Best to let it rest for a year. Don't ask how I know this -- an expensive experiment.