need help. i have an ezclone cloning machine and i can't get it to work.

i take cuttings according to the ways i've read about.
1/4 inch below node, 45 degree angle, dipping immediately in clonex. the cuttings are 4-5 inches tall, a couple of leaves on top. i've read about wounding but haven't tried it---yet. the mothers are healthy, in vegative state. i have read something about the ma's shouldn't be hyped up with nitrogen. this could be a problem. i've been using a grow juice with lots of nitrogen. i've decided to flush with pure water a couple of waterings before taking anymore cuttings.
into the machine they go.
there are compact flourescents, a 6 bulb fixture. its raised to 17 inches above the top of the machine. i leave the lights on 24/7.
my ph averages 5.5-5.7, water temp--well i have a problem with that. it goes up, but on average it measures 71-78. air temp 79, relative humidity 48 percent.
i have a timer on the spray, 1 on 3 off i think is the cycle.
i'm using a root stimulator i bought from a local grow shop.
without fail 6-7 days in, no roots and the leaves begin to yellow.
i think that's about it.
any suggestions?
thanx in advance!