Access2007 filtered form #error on calculated control in footer

[eitanma]

Hi
I have total controls in the footer section which perform aggregate actions on the filtered data
in the detail section.

When the form opens the detail section shows all the data, without a filter.
When there is no filter applied, all of the calculated controls in the footer show #error
when i apply a filter, the data is been calculated correctly

what am i doing wrong?

thanks