Yes, they do zing more when played along the line of strings rather than across! (i.e they zing more when played normally), so I guess you must be right…
I have already done what you suggested, but with a paperclip and that made it temporarily go away (see my first post), do you think it’s worth trying again with some card?
The harp is strung haphazardly in pedal light gut – I say haphazardly because some of the strings are way above or below pedal light tension. I’m beginning to wonder whether the ones strung below tension correspond to the zinging strings…and of course you are right about the high strings – the lowest zinging string is the 3rd A…