can someone tell me why my PVA is spider-webbing?

[clonesix]

I went to spray PVA last night, and I kept getting spiderwebs out of the gun. I lowered the air pressure, still spiderwebbing. I added a little alcohol to thin the mix, and still webbing.

I just spray material from this bottle two days ago, and didn't have this problem.

Can anyone explain this?