why balance-sheet report's totals-get-balance fails in my report.

[Larry Evans]

I copied the balance-sheet.scm totals-get-balance to the
following code:

         (gnc:html-table-append-row/markup!
           table
           (if (odd? row-num) "normal-row" "alternate-row")
           (list
             (gnc:print-date from-date-tp)

             (gnc:make-html-table-cell/markup
               "total-number-cell"
               (let
               ;bindings:
                 (( totals-get-balance
                    (lambda
                    ;args:
                      ( account
                      )
                    ;body:
                      (gnc:account-get-comm-balance-at-date
                       account
                       from-date-tp
                       #f
                      )
                   );;lambda
                  );; totals-get-balance
                 )
              ;body:
                 (totals-get-balance (car accounts)
                 )
               );;let
             );;"total-number-cell"
             ":Begin Balance"
           )
         );;gnc:html-table-append-row/markup ":Begin Balance"

yet the output produced is:

01/01/2006	#[procedure]	:Begin Balance

Why is #[prodedure] output instead of some number?
TIA.