I had a Laser II with a comparable snuffer system (continuous line to both raise and snuff the spinnaker,) but I never had a problem like this with it. Its been years, but I think the fabric of the spinnaker was thicker on my Laser II. Maybe that's why I didn't have this problem, or maybe my halyard was thinner...

I've sailed Hobies (from Wave up to Tiger,) but I never used a spinnaker on a cat.