Why are my clones dying

I have a 165 site clone machine at my buddies house.
I filled it with clones, and now a week later all the stems inside the clone machine have turned to mush.
The last batch we took was about a 98% success rate.
We use distilled water, mild veg nutes, about 200 ppm of flora nova, and ph between 5.5-6.5 is maintained.
Water temp is about 65-70 degrees.
The machine sparays continuous, with flouresent lights 24 hours.
This happens quite often, and I cant figure out why its happening.
Any advice would be much appreciated.

too wet!

put it on a timer 1min on 5 min off, or somehow get more dry conditions.

thanks for the advice,,, thats what I was kinda thinking it was, just too much water being misted, but then again, Im thinking its something else because at my other buddies house we are using a 45 site clone machine and theres not really any problems with that one and its about 95% success rate.
I was thinking maybe after i took the clipping and my buddy put them in the neopreme inserts that maybe he put them in the machine a little to firmly and it pinched them off.
He said he did it the same as before.
It seems like it happens every other time we put clones in it.. Its a real bummer to see that many of them die off.
Im thinking of going back to the wool, but it takes longer for the roots to show and I dont like having the wool in the net cups with the hydroton in the aero machine, that makes them get soggy also.
what to do, what to do.....