This is the log:
High Leaving Monitored Scope (PostResolveRequestCacheHandler). Execution Time=11,9294491338983 8e710563-701b-42b3-b152-6f7905639587
02/22/2013 14:39:25.77 w3wp.exe (0x1738) 0x131C SharePoint Foundation Runtime tkau Unexpected System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.Web.CommandUI.Ribbon.CreateRenderContext(CUIDataSource uiproc) at Microsoft.Web.CommandUI.Ribbon.Render(HtmlTextWriter writer) at Microsoft.SharePoint.WebControls.SPRibbon.Render(HtmlTextWriter writer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) at System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) at System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.HtmlControls.HtmlContainerControl.Render... 8e710563-701b-42b3-b152-6f7905639587
02/22/2013 14:39:25.77* w3wp.exe (0x1738) 0x131C SharePoint Foundation Runtime tkau Unexpected ...(HtmlTextWriter writer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Page.Render(HtmlTextWriter writer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) 8e710563-701b-42b3-b152-6f7905639587
02/22/2013 14:39:25.77 w3wp.exe (0x1738) 0x131C SharePoint Foundation Monitoring b4ly Medium Leaving Monitored Scope (Request (POST:http://loamos01:82/sites/pm/TEST%20FTP/Forms/AllItems.aspx?InitialTabId=Ribbon%2EAsposeNetwork%2EDocLibraryTools&VisibilityContext=WSSTabPersistence)). Execution Time=128,786479845902 8e710563-701b-42b3-b152-6f7905639587