On the recommendation of one of the nurses in one of the hospitals - her husband is a lifter - I went to see a coach, Pete Upham, who runs Shire Speed and Strength gym in Sutherland in Sydney. The gym is really cool: not a single mirror on the wall, no machines, just free weights, about five pairs of stands for squatting, oly lifting platform and couple of large tyres.
Getting advise from a coach is useful, to say the least. He filmed my squatting and dissected my technique into little phases, and then corrected them. I worked up to the set of five with 57.5 kg and decided to call it quits. I highly recommend coach Upham and his gym.
I hope the lesson is useful, and I will be able to progress in squat. I really like it. Besides, I have a cool squatting cage in my little gym in the garage, it shouldn't just stand there! In two weeks I have an appontment for the deadlift.