一个有趣的VB问题,不知高手能否回答？？是Bug吗?

并不是非要这么做，只是不明白为什么？
窗体放了一个MSFlexGrid1和Text1
MSFlexGrid1最小行高400,Text1的visble属性Flase

问题:
事件:鼠标点击MSFlexGrid1的单元格,
三种操作：1.设断点于Private Sub MSFlexGrid1_EnterCell和
Private Sub Text1_LostFocus()
2.只设断点Private Sub Text1_LostFocus()
3.不设任何断点

三种操作方式Text1的出现情况不同，
1.Private Sub Text1_LostFocus()根本不执行，Text1一直显示
2，3. Private Sub Text1_LostFocus()执行，Text1有时显示

尝试发现去掉
If Me.Text1.Visible And Me.Text1.Enabled Then
Me.Text1.SetFocus
End If
则三种方式一样

关键问题：为什么Private Sub MSFlexGrid1_EnterCell，设断点与不设断点完全不同？？？


代码如下：
Private Sub Form_Load()
Me.MSFlexGrid1.Cols = 5

Dim i As Integer

For i = 0 To 4
Me.MSFlexGrid1.ColWidth(i) = 2000
Next

For i = 1 To 10
Me.MSFlexGrid1.AddItem ""

Me.MSFlexGrid1.TextMatrix(i, 0) = "aaa"
Me.MSFlexGrid1.TextMatrix(i, 1) = "bbb"
Me.MSFlexGrid1.TextMatrix(i, 2) = "cc"
Me.MSFlexGrid1.TextMatrix(i, 3) = "dd"
Me.MSFlexGrid1.TextMatrix(i, 4) = "fff"
Next
End Sub

Private Sub MSFlexGrid1_EnterCell()
Me.Text1.Visible = True

Me.Text1.Left = Me.MSFlexGrid1.Left + Me.MSFlexGrid1.ColPos(Me.MSFlexGrid1.ColSel) + 50

Me.Text1.Top = Me.MSFlexGrid1.Top + Me.MSFlexGrid1.RowPos(Me.MSFlexGrid1.RowSel) + 50
Me.Text1.Width = Me.MSFlexGrid1.ColWidth(Me.MSFlexGrid1.ColSel)
Me.Text1.Height = Me.MSFlexGrid1.RowHeight(Me.MSFlexGrid1.RowSel)

Me.Text1.Text = Me.MSFlexGrid1.TextMatrix(Me.MSFlexGrid1.RowSel, Me.MSFlexGrid1.ColSel)

CurrRow = Me.MSFlexGrid1.RowSel
CurrCol = Me.MSFlexGrid1.ColSel
If Me.Text1.Visible And Me.Text1.Enabled Then
Me.Text1.SetFocus
End If
End Sub

Private Sub Text1_LostFocus()
Text1.Visible = False
End Sub