Conditional formatting. Highlight cells that meet a criteria but ignore blank cells.

-I have two columns of numbers.
-There are blank cells in each column that appear sporadically.
-In each row of numbers, I want to create a conditional format that highlights a cell if the number in the cell is greater than a designated value.
-Currently I am using: Conditional formatting 'formula' =ABS(C4-C3)>.1 OR =ABS(D4-D3)<.1 for the respective column of numbers.
-This formula does not work now that I have empty cells between the values. All the blank cells are highlighted and the subtraction can not take place if the cell is blank.
-I want the formula to not see the blank cells and make the comparison between the first vale and the next vale in the series.
-I do not want to sort the blank rows out and then replace.
Thank you,
Daniel

Please see attachment: TESTAE042701.csv

Please see revised attachment...
Column C row 22.

This is the instance where the formula will not highlight the value. Above or below doesn't matter. These numbers are plotted linearly and any values that are not within the specified range will create spikes. I am trying isolate the "bad" values.

Thank you.

Please see attached .xls. Thank you.