When inserting new row on sheet 1, cell ref on sheet 2 doesn't reflect the insert

Hi all,

I have an excel file (excel 2003), containing 3 sheets. On sheet 1 I have some basic data which needs some sorting and manipulation. On sheet 2 and 3 I want to automatically create some lists based on the data from sheet 1.
I use the formula; =IF('SHEET1'!A1="";"";' SHEET1'!A1) on sheet 2 and 3 to prevent errors if there are any empty cells.
Now my issue is that I need to insert new rows and add new data to sheet 1, but I can not get sheet 2 and 3 to reflect the insert of the new row, and the new data. I only get a gab in cell references; C15, C16, C18, C19 on sheet 2 if I insert a new row 17 on sheet 1.
How can I get around this issue ??