Sometimes globes develop a haze on the inside of the glass, and sometimes the liquid will develop a semi-haze like that. You can usually tell if it's on the inside of the glass, as there will inevitably be 1 or 2 spots where the haze has rubbed off, making it obvious. If it's in the liquid, it's been my experience that it won't clear. Some people have had luck chilling their globes and then running them, but you have to wait until the globe is back to room temp first. I have tried that, and it seemed to work, but the effects didn't last for me.
Yeah I have some globes like that. Funny thing is most of them are black wax. One is a green from the Neon series 52 oz from a few years ago. Carol had Goo Kit goo do that also, she contacted them and they think it is from wax break-down, maybe from running the globes got for too long. That makes sense to me because the green neon has been ran a lot since I got it and many days it's been ran for 10 hours or more.
The black wax ones were all acquired second hand so I don't know their run history.