with rollup

When I use "With rollup," I am getting totals on columns which are numeric,
however, non-numeric columns are copying down to the rollup column (i.e. the
last column's non-numeric columns are being duplicated on the rollup
column).

For example. if I order by date with rollup and, I am also outputting
emplyee, and some numeric value , at the rollup row, the totals appear, that
date, of course, properly appears, but the employee name from the previous
row is also duplicated on this row.

How can I avoid that? Thanks, Ike