Spin Collapsing

Seems like in my last couple of outings, my spinnaker luff is collapsing more than it used to. I used to be able to keep the luff "winking" at me, and play the sheet to keep it doing so.

Is this a luff tension issue? I checked it and it seems right.

In what wind? High or light? How old is the spin? Is it "Blown Out" ie. stretched out of shape? That will do it. I have two spins, one flat, the other full, the flat one is much easier to keep "on the edge" without collapse, the full one is too full for tight reaching and when it does collapse it goes all the way, but it's good for going deep in a blow.

More in lighter winds, but I've noticed it in moderate winds as well.

Spin is an '08 so more on the full side. It was in great shape when I got it. I don't sail that much. Around 4 days a month from May - Sept. How can you tell if it is time for a new one.

By 08 they were the flatter cuts.
Look at your luff tension, it should be 45-90 degrees at most on the twist grab.
Also if you have never done anything with it, look at the luff tension line. This should be tied about 1/2" tighter then the sail luff itself. This line sometimes has a big effect on flying the spin in certain conditions.