weird haze from my AB light

I have been using the same lights for 2 years in my studio. Yesterday I was getting a weird haze from my 1600 AB with a 1x4 Photoflex softbox. I was doing some test shots first, and they looked horrible. The top half of the photo was all messed up but the bottom half was ok. You can see the haze in the upper right hand corner. Can anyone tell me what was happening? I have 2 AB 1600's and I tried changing out the lights in case it was a problem with that light but got the same results?