the seat is back correctly, and slammed a few times !!!
i have put some high density 25mm wide, 20mm thick foam near the clip.. this makes a constant push back on the back of the seat, which keeps the clip "gripping" the metal catch.
also taken out the parcel shelf, which makes a huge difference !!!
i intend lining the parcel shelf area, the bits that touch the plastic, with sticky back felt