At the end of the last episode they showed (as they often do) a "Next time on Mile High..." trailer, immediately followed by the Sky One announcer saying "Mile High returns later in the year" or words to that effect. I believe there were 17 episodes made for this run, why they only showed a handful of them is anybody's guess!
I actually emailed Sky One a couple of months before they began to transmit this last series, to ask "if" there was another series commissioned and if so when it was to be aired! The reply I got suggested that they knew a new series had been commissioned but had no idea when it was to be broadcast. At the same time I was reading (on www.digitalspy.co.uk forums I think) that the new series had already started broadcasting in Australia! Am I the only one who thinks that perhaps Sky TV doesn't know it's posterior from it's mid-arm ball-and-socket hinge joint??