I noticed when I logged in through the admin panel I was presented with the String resource name and not the value for "signin.aspx.*" (see image) . When I went to see if the value was set for that string resource through the admin site, I was not able to browse to that resource. The last resource was "showproduct.aspx.42". I did however open the Excel file and see the "signin.aspx.8" resource.
Any ideas why this is occurring?