ORA-00942 Table Or View Does Not Exist - First connect only

Personally I would use the direct oracle access components if the application will not change from looking at an oracle database.

http://sourceforge.net/projects/delphioci/

Try monitor your application data excahage with server. Something like:

fExecuteTime     :dword;
...

procedure TDM.dbConnectionWillExecute(Connection: TADOConnection;
  var CommandText: WideString; var CursorType: TCursorType;
  var LockType: TADOLockType; var CommandType: TCommandType;
  var ExecuteOptions: TExecuteOptions; var EventStatus: TEventStatus;
  const Command: _Command; const Recordset: _Recordset);
var
  i,j:integer;
  infoStr:String;
  tmpParameters:Parameters;
begin
  if gDebugMode then
    MonitorEvent('WillExecute.. ',[]);
  fExecuteTime:=GetTickCount;
  if gSqlMonitor and gDebugMode then
  begin
    MonitorEvent(CommandText,['']);
    if Assigned(Recordset) then
    begin
      for i := 0 to (dbConnection.DataSetCount-1) do
       if Assigned(dbConnection.DataSets[i].Recordset)
        and (Recordset = dbConnection.DataSets[i].Recordset) then
        if (dbConnection.DataSets[i] is TADODataSet)
          and (TADODataSet(dbConnection.DataSets[i]).Parameters.Count > 0) then
          for j:=0 to TADODataSet(dbConnection.DataSets[i]).Parameters.Count - 1 do
          begin
            infoStr:='P['+IntToStr(j)+'] '
            + TADODataSet(dbConnection.DataSets[i]).Parameters.Items[j].Name+' = ';
            if Not VarisNull(TADODataSet(dbConnection.DataSets[i]).
               Parameters.Items[j].Value) then
              infoStr:=infoStr
              + String(TADODataSet(dbConnection.DataSets[i]).Parameters.Items[j].Value)
            else
              infoStr:=infoStr + 'Null';
            MonitorEvent(infoStr,['']);
          end;
    end;
    if Assigned(Command) then
    begin
      tmpParameters:=Command.Get_Parameters;
      if (tmpParameters.Count > 0) then
        for j:=0 to tmpParameters.Count - 1 do
        begin
          infoStr:=tmpParameters.Item[j].Name+' = ';
          if Not VarisNull(tmpParameters.Item[j].Value) then
            infoStr:=infoStr + String(tmpParameters.Item[j].Value)
          else
            infoStr:=infoStr + 'Null';
          MonitorEvent(infoStr,['']);
        end
    end;
    MonitorEvent('',['']);
  end;
end;

procedure TDM.dbConnectionExecuteComplete(Connection: TADOConnection;
  RecordsAffected: Integer; const Error: Error;
  var EventStatus: TEventStatus; const Command: _Command;
  const Recordset: _Recordset);
begin
  Self.fExecuteTime:=GetTickCount-Self.fExecuteTime;
  if gDebugMode then
    MonitorEvent('Execute time: ' + FloatToStr(Self.fExecuteTime / 1000) + ' s.',[]);
end;