Yes, I think Ian and Roger are closing in on the issue. What I didn't
mention in the original post is that the columns that create the tree
structure contain simple formulas in each cell, i.e.:

col c =IF(A1="1", B1, "") [i.e Assets]
col d =IF(A1="2", B1, "") [i.e Current Assets]
col e =IF(A1="3", B1, "") [ie. Bank Accounts]
col f =IF(A1="4", B1, "") [i.e Wachovia Bank Account]

I'd guess that returning the empty string might be the problem. Is there a
different solution?

Thanks, JD