Thanks for those, Les. I'll try them out later since I'm using Antonia at the moment and she could do with some jewellery, I think.

Rather than turn off the gravity simulation altogether, it should work better to turn the appropriate PointAt dial down from its default 1.000 value, until the offending earring lies against Antonia's neck. Using that method, you still have the advantage of gravity on the 'free' earring. You could rename the PointAt dial to Gravity, perhaps, to act as a reminder.