Looks like heat stress. Even though the glass tubing on CFLs doesn't get all that warm, the ballast in the base puts out a lot of heat. Have a few of those in a confined space, and you can get heat stress. When I use CFLs, I keep them within a few inches of the leaves, giving me around 45k lumens. But I also have fans blowing on the ballasts, and good ventilation in whatever space I'm growing in.