I get this error trying to send a PM to a user. It happens in a couple different locations (viewing their profile and hitting the PM link under their post):

[IndexOutOfRangeException: There is no row at position 0.]

System.Data.RBTree`1.GetNodeByIndex(Int32 userIndex) +1943315

System.Data.RBTree`1.get_Item(Int32 index) +17

System.Data.DataRowCollection.get_Item(Int32 index) +11

YAF.Pages.pmessage.Page_Load(Object sender, EventArgs e) +1377

System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15

System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +33

System.EventHandler.Invoke(Object sender, EventArgs e) +0

System.Web.UI.Control.OnLoad(EventArgs e) +99

System.Web.UI.Control.LoadRecursive() +47

System.Web.UI.Control.LoadRecursive() +131

System.Web.UI.Control.LoadRecursive() +131

System.Web.UI.Control.LoadRecursive() +131

System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1436