Temps in Viv are Driving me Crazy! HELP...

[Cam5]

A very basic question, and I have a talent for making things more difficult than needed but:

We have 2 '07 corns.
Housed separately in the following...
20 gallon long viv with sliding screen.
Shaved Aspen substrate.
3 hides...warm end, middle, cool end.
Climbing branch thing in middle.
Water dish on cool end along edge.
Two thermometers on the lower wall opposite ends for a general idea.
One probe thermometer in warm hide.
One UTH directly under warm hide (ExoTerra Rainforrest UTH)
One red 50 watt bulb heat light over warm-middle end on dimmer at about 25% capacity.

Temp in warm end ambient 75*F
Cool end ambient 70*F
In the hide UNDER the substrate 90*F
On top of sub strate 77*F...
ARGH!!!

I know the temp IN the hide should be 80-84*F no more no less.
Where should the probe be?

Thank you in advance for any advice so that I do not need to seek out Rogaine soon

My camera is not cooperating...I will try to post pics if it helps.
Our little Phantom boy is a goofball anyway...he was sitting on top of the climing area today with the heat bulb off!!!!
He does stuff like that a lot...sitting out the day after he's eaten and I set him in fron tof his warm hide and he goes in.