Freeze columns and rows doesnt seem to work

I am trying to freeze rows 1,2,3 and 4 along with columns a,b,c,d,e,and f. But for some reason it will only freeze a total block (a thru to n) and (1 thru to 26) any solution would be much appreciated. Just noticed that the row height on some of the rows needs resetting to 20. but this dont affect the freezing