In reply to Sandstone Stickman:
What kind of load is on when it's doing that? It's a problem that gets worse as the load is lighter, for example while abseiling down sloping "steep ground" rather than vertically..
That's why the newer version has a button on the handle - holding the button down with your thumb prevents the anti-panic malarky from engaging.
If you try a short vertical abseil and it's ok with bodyweight on it that's probably normal.