Access violation at address 40539CAF in module GDS32.DLL Read of address 36317836

Hello

I have a button on a form that summarizes a list of material items into a
TList and displays them in a TMemo in another form. On my local workstation
I pretty much have everything working correctly, but when I connect to a NT
server (I have tried many different servers) I get an Access violation at
address 40539CAF in module GDS32.DLL Read of address 36317836.

The first time I run the function (press the button) it works perfect (on
the network). The second time I always receive the error. This same database
on the local machine never has a problem.  I uninstalled and reinstalled
Interbase on the local machine and the server with the same result.

The function is a simple SQL Query. I have tried Prepare/Unprepare and
nothing seems to work. I am using Interbase 6.01 with IBO_3_6_A. The
GetTakeoffItems is a TIBOQuery in a TDataModule, the TIBODatabase is in
another TDataModule.

procedure TAppCalcPlanBase.LoadTakeoff(ALinkID: integer);
begin
  if ALinkID < 1 then exit;
  with GetTakeoffItems do begin
    GetTakeoffItems.Params[0].AsInteger := ALinkID;
    Open;
    while not eof do begin
      with TakeoffAdd(GetTakeoffItemsMATERIALID.AsInteger) do begin
        Units := Units + GetTakeoffItemsUNITS.AsFloat;
      end; {with}
      next;
    end; {while}
    Close;
  end; {with}
end;

The SQL
SELECT
TAKEOFFITEMS.SEQNO,
TAKEOFFITEMS.MATERIALID,
TAKEOFFITEMS.UNITS
FROM TAKEOFFITEMS
WHERE TAKEOFFITEMS.LINKID = :LinkID

Thanks for the help
Steve Johnson