ActiveDocument.FullName includes the entire path so you are simply saving the file over itself. Try
Code:
Sub Savetolocation()
Dim sLocation As String
sLocation = "C:\Users\dwirony\My Documents\Overflow Folder\" & ActiveDocument.Name
ActiveDocument.SaveAs2 FileName:=sLocation, FileFormat:=wdFormatXMLDocument, CompatibilityMode:=14
End Sub