For several months I have had problems with reception using the Hills HSM075 Freeview satellite receiver. In the morning and evening/night it seemed to work perfectly. It was fine in the afternoons (say from noon until 6pm) provided I didn't change TV channels or change from TV to radio. If I did attempt to change channels in the afternoon it would lose it. Signal strength was fine but signal quality dropped to zero. The error message suggest I check the cable to the satellite dish! Turning off and rebooting occasionally fixed the problem but only rarely. It was worst on sunny days. I have read that the signal from the satellite can be swamped by radiation from the sun if it's in the sky in a similar direction to the Optus D1 satellite. I figured that was the problem, and that I'd just have to put up with it and avoid changing channels in the afternoon.
Today I installed a DishTV S9020DVD which is not only a Freeview satellite receiver but also plays DVDs, MP3s and (the feature I wanted) can record programmes onto an external USB drive.
The good news is that I have been able to change channels etc on the DishTV unit this afternoon with no problems despite it being a bright sunny day. The signal strength is 83-85% and quality 70-72%. The cable to the satellite dish is approx 25m and the dish itself is only 60cm diameter.
The bottom line - based on my experience I can't recommend the Hills DVB-S HSM075, but the DishTV S9020DVD is a great improvement. It seems better able to lock on to the signal than the Hills unit despite radiation from the sun.