Can't close an Excel workbook

[Sven62]

Take a look at this... From a userform. I call a macro that opens a workbook called Training_Priority. After it opens I can't close it unless I minimize then maximize it. Then I can close it. What is up with that?

Private Sub CommandButton6_Click()Unload Me
Call Priority
End Sub

Sub Priority()Workbooks.Open FileName:="S:\Train Track\Docs\Training_Priority.xls"
End Sub