[5分]修改窗体，修改后保存返回数据表窗体是数据加载慢 约有30秒

这是我的修改窗体保存按钮的代码

Private Sub CmdOK_Click()                 'Click OK button
    DoCmd.SetWarnings False
    DoCmd.RunSQL "Delete * from Pesticide_Target Where PIDS = '" & selectstr & "'"
    DoCmd.RunSQL "Delete * from Pesticide_Vendor Where PIDS = '" & selectstr & "'"
    DoCmd.RunSQL "Insert Into Pesticide_Target (PIDS,PTAG_E,PTAG_C,TAG_Risk,Inputer,Up_Date)" _
               & " Select PIDS,PTAG_E,PTAG_C,TAG_Risk,Inputer,Up_Date from Pesticide_Target_Temp "
    DoCmd.RunSQL "Insert Into Pesticide_Vendor (PIDS,PNE,PNC,Dosage,Active_Principle,PHol,PA_AP,PVendor,PRN,Comments)" _
               & " Select PIDS,PNE,PNC,Dosage,Active_Principle,PHol,PA_AP,PVendor,PRN,Comments from Pesticide_Vendor_Temp"
    DoCmd.SetWarnings True
    
    Me.Refresh
    DoCmd.Echo False                                               'To prevent screen flash
    Forms!usysfrmMain!frmChild.SourceObject = "frmPesticide_child"  'Refresh child form after edit
    DoCmd.Echo True                                                'Turn on Screen Echo to prevent black display
    Forms!usysfrmMain!frmChild.Form.TimerInterval = 300           'To trigger Child Form's Timer procedure 0.3 seconds.
    DoCmd.Close acForm, Me.Name                                    'Close Currenct Form
End Sub

我自己测试单步执行时一直到End Sub 没有问题速度很快，但是从End Sub 后要加载数据表窗体并将记录定位到刚才修改的记录时速度相当慢，约30秒。我程序的其他修改窗体不存在这个问题。如果我将这一句

 Forms!usysfrmMain!frmChild.Form.TimerInterval = 300           'To trigger Child Form's Timer procedure 0.3 seconds.

隐藏掉，跳过不执行，则速度奇快，我百思不得其解。只有这个窗体存在这个问题。请高手指点，谢谢