Thank you. I've not met this problem, but I've learned something new against a future 'Murphy Bomb' such as low-flying cat..

Autumn has arrived, the cats are eating for twice their number: On cool evenings, 'Ms Robbie the Ratter', our tabby huntress, will come in from patrol, leap onto my desk, march to-and-fro purring, then sprawl across my right arm. Fortunately, I use a track-ball...