Array Losing Values

I have a script that is conditionally assigning a value of one to a cell of a multi-dimensional array as it loops through it. 

Count = 0
      ClientData = Session ("ClientData")
      for each item in ClientData(ExpertReportList)
        if Count = CLng ( Request("DeleteItem") ) then
          item(EXPERT_REPORT_DELETE) = 1
        end if
        Response.Write(Cstr(item(EXPERT_REPORT_DELETE)))        
        Count = Count + 1
      next
      for each item in ClientData(ExpertReportList)
        Response.Write(Cstr(item(EXPERT_REPORT_DELETE)))
      next
      Session ("ClientData") = ClientData

The problem is that one the first pass through, the Response.Write is showing the correct values; but, on the second pass through, all of the values are back to the original values before they passed through the loop.

Any ideas what is causing this?