Well thanks for the suggestions, I tried steeping the tea for longer, 6 mins, used a little more tea than I would usually and had it constantly boiling - it was much the same, a weak smokey tasting brewy, earthy but without the sweetness you get with an Assam.
As I said I got this from quite a reputable suplier, a Chinese food and tea stall at an outdoor market in Manchester, UK. There were several big sacks of Chinese teas, this Keemun, several Lapsang Souchongs (which I avoided) and a beautiful Yunnan Gold which is spectacular.
Shah82 are you suggesting that I brew the tea for a minute, remove the leaves, let it cool, boil the tea, brew for 30 seconds and so on and so on? I'm a little confused. Cheers.