I feel gutted that I could be so stupid. As a user for the last couple of years I've been very pleased with the product, content you might even say.
When I heard about a new version I thought "g ...
Just a guess but mobiles give off a fair bit of RF. Have you tried a capacitor of a similar value to the scope probe on the same pin to ground? Might give you a pointer. I've had circuits do similar w ...