Created Unassigned: Unable to connect to a feed if a proxy has been specified via module [3370]

I'm trying to use Nuget.Core functiaonality in my application. Everything works fine until I specify a proxy in my web.config

```
<system.net>
<defaultProxy enabled="true" useDefaultCredentials="false">
<module type="Werp.Utils.ProxyFromAppSettings, Werp.Utils" />
</defaultProxy>
</system.net>
```
This setup work perfectly fine for other parts of my app using WebRequest, but nuget fails to use these proxy settings:

```
var agg = PackageRepositoryFactory.Default.CreateRepository("http://demo.****.com/nuget/nuget");
agg.GetPackages();
```
I got this:
```
System.NullReferenceException occurred
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=NuGet.Core
StackTrace:
at NuGet.ProxyCache.IsSystemProxySet(Uri uri)
InnerException:

```
And this:
```
System.InvalidOperationException occurred
HResult=-2146233079
Message=Could not connect to the feed specified at 'http://demo.oreodor.com/nuget/nuget'. Please verify that the package source (located in the Package Manager Settings) is valid and ensure your network connectivity.
Source=NuGet.Core
StackTrace:
at NuGet.DataServiceQueryWrapper`1.Execute[TResult](Func`1 action)
InnerException: System.NullReferenceException
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=NuGet.Core
StackTrace:
at NuGet.ProxyCache.IsSystemProxySet(Uri uri)
at NuGet.ProxyCache.GetProxy(Uri uri)
at NuGet.HttpClient.TrySetCredentialsAndProxy(WebRequest request)
at NuGet.HttpClient.InitializeRequest(WebRequest request)
at NuGet.DataServicePackageRepository.OnSendingRequest(Object sender, SendingRequestEventArgs e)
at System.Data.Services.Client.DataServiceContext.CreateRequest(Uri requestUri, String method, Boolean allowAnyType, String contentType, Version requestVersion, Boolean sendChunked)
at System.Data.Services.Client.DataServiceRequest.CreateResult(Object source, DataServiceContext context, AsyncCallback callback, Object state)
at System.Data.Services.Client.DataServiceRequest.Execute[TElement](DataServiceContext context, QueryComponents queryComponents)
at System.Data.Services.Client.DataServiceQuery`1.Execute()
at System.Data.Services.Client.DataServiceQuery`1.ExecuteInternal()
at System.Data.Services.Client.DataServiceQuery.Execute()
at NuGet.DataServiceQueryWrapper`1.Execute[TResult](Func`1 action)
InnerException:

```