Hi

Now, I didn't have a very close look to your code, but one thing isn't correct:
I gave you yesterday the formula, and maybe it looked odd to you that it will work. But it will:
=AND($I3>$S$1,$I3<$U$1)

The thing is, excel expects a result either True or False. On just this result it's decided if the format gets applied or not.
The formula you use returns a result, the else-part returns text (empty string). In case your result is numeric, every number > 0 is interpreted as True. A emtpy string maybe will bring up some confusion.

Another thing, you will have to check:
Inserting a formula when references aren't absolut is a tricky thing. Your reference $I3 might change the reference of row 3 to another row, in case a cell is selected not within row 3.