Excel conditional formatting and inserting a new row

Gah, using Excel 2007 (at work). I have a conditional format rule the greys out all but the first occurrence of each unique value in a column (they are sorted). I took it from here.

Code:

---

Formula: =A2=A1
Applies to = $A:$A

---

If I then insert a new row e.g. 7, Excel "helpfully" splits my formula like this:

Code:

---

Formula: =A2=A1
Applies to =$A$1:$B$5,$A$8:$B$65536
Formula: =A8=A6
Applies to =$A$6:$B$7

---

The conditional formatting doesn't work on the new row 7. Any idea how to stop this annoying feature :confused: