IIS Express: Network mapped Virtual Directory throws error 'This user can't sign in because this account is currently disabled.'

We use a network mapped virtual directory setup through '.vs\config\applicationhost.config'

<site name="Web" id="2">
    <application path="/" applicationPool="Clr4IntegratedAppPool">
        <virtualDirectory path="/" physicalPath="C:\code\projectname\src\Web" />
        <virtualDirectory path="/media" physicalPath="\\myserver\Media\projectname\media" />
    </application>
    <bindings>
        <binding protocol="http" bindingInformation="*:80:www.projectname.local" />
        <binding protocol="http" bindingInformation="*:443:www.projectname.local" sslFlags="1" />
    </bindings>
</site>

This worked flawlessly until we physically moved office to a new location. So our network changed. And now I get this error:

[IOException: This user can't sign in because this account is currently disabled.
]
   System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) +1091
   System.IO.Directory.InternalCreateDirectory(String fullPath, String path, Object dirSecurityObj, Boolean checkHost) +1394
   System.IO.Directory.InternalCreateDirectoryHelper(String path, Boolean checkHost) +92
   Umbraco.Core.IO.IOHelper.EnsurePathExists(String path) +43
   umbraco.presentation.EnsureSystemPathsApplicationStartupHandler.ApplicationInitialized(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext) +69
   Umbraco.Core.ApplicationEventHandler.OnApplicationInitialized(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext) +50
   Umbraco.Core.CoreBootManager.<Initialize>b__28_0(IApplicationEventHandler x) +379
   Umbraco.Core.EnumerableExtensions.ForEach(IEnumerable`1 items, Action`1 action) +167
   Umbraco.Core.CoreBootManager.Initialize() +1177
   Umbraco.Web.WebBootManager.Initialize() +19
   Umbraco.Core.UmbracoApplicationBase.StartApplication(Object sender, EventArgs e) +263

[HttpException (0x80004005): This user can't sign in because this account is currently disabled.
]
   System.Web.HttpApplicationFactory.EnsureAppStartCalledForIntegratedMode(HttpContext context, HttpApplication app) +517
   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +185
   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +168
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +277
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +369

[HttpException (0x80004005): This user can't sign in because this account is currently disabled.
]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +532
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +111
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +714

As soon as I remove the media virtualDirectory it works just fine.

When I try to access the same URL (\\myserver\Media\projectname\media) via Explorer is just works fine.