Hi,
my New F-1 (FN standard prism) seems to have the same problem. Sometime the needle doesn't move when I half press the shutter (as if it was sticky).
When I aim upward, the needle usually move on half shutter press.
When I aim downward, the needle often doesn't move on half shutter press.
It seems to work a little better recently, maybe the way of storage helps (left camera side down ?)