UNC path failure

[wasabii]

System.Net.Http.HttpRequestException System.Net.Http.HttpRequestException: Error while copying content to a stream. ---> System.IO.FileNotFoundException: Can't find a view with the name 'SignIn.cshtml' or 'SignIn.vbhtml in the '\Views' folder under path 'ad.isillc.com\web\inetsrv\sites\ISIS.Partner.Authentication'

My site is mapped to a DFS path. Clearly, it's stripping off the leading \, and thus failing. Error is probably in RazorViewLocator somewhere.