Can clotted cream be made with UHT cream? I've followed a couple of recipes for clotted cream without success and it seems that pasteurization is the issue. I'm told that I need to use either unpasteurized cream or cream that has been low-temperature pasteurized.

All I can find here in Stockholm is cream pasteurized at higher temperatures (85 degrees C). Does anyone know why high temperature pasteurized cream doesn't work for clotted cream? Does anyone have a trick up their sleeve to get it to work?
This recipe seems to suggest that using UHT cream will work, but that it will be a bit softer than if non-UHT cream is used.  Perhaps you can compare your technique to the one suggested in this recipe to see where it diverges.