type mismatched error 13 on general text ???

hi
I have a loop that check the following :

If ws3.range("D" & i).value = "DEBLOCK"  Then

the cells in D has a formula :

=IF(AND(B2 < 20%, C2 ="U"),"DEBLOCK","")

the formula works perfect, the cell is not formatted (general)


on a time that a DEBLOCK appear in a cell and the loop detects it, I get a debug window on the "IF" line

Type mismatched error 13, and I see in watch window error 2042 variant/error


anyone understand this ???

Thanks
Chris