I have just had a quick look and you can get lots of the 0.1p flights inc all taxes and charges (or not in this case). You just have to be very picky on the dates and times of the flights. For example, the morning STN - BHD flights seem to be all virtually free, where as most of the evening STN - BHD are all with taxes. They are on there you just have to look for them quite hard :-)
I also would have liked more STN routes available in this offer.