Drilldown not drilling down

Hi all,

I have the following formula in the row header range:

=IF(COUNTIF($L$28:L30,L30)<>6,EVDES(M30,$K$2),"Word")

If the range, is only EVDES(M30, $K$2) then drill down is good to go.

However, with the formula the drill-down does not function.

Any ideas?

Thanks,

Greg