Mouse_no_longer_move

[Hack]

Try

Private Declare Function SetCapture Lib "user32" (ByVal hwnd As Long) As Long 
Private Declare Function ReleaseCapture Lib "user32" () As Long 
Private Declare Function GetCapture Lib "user32" () As Long 
 
Private Sub Picture1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If (X < 0) Or (Y < 0) Or (X > Picture1.Width) Or (Y > Picture1.Height) Then 
       ReleaseCapture 
       'the mouse is no longer over the picture box, so do whatever
ElseIf GetCapture() <> Picture1.hwnd Then 
       SetCapture Picture1.hwnd 
       'the mouse is over the picture box, so do whatever
End If
End Sub