Web API File Upload Problems

Using MVC 4 I'm trying to build a Web API controller where you can upload an image. After the upload is complete the controller should save the image in the database. Here is my code:

[HttpPost]
public void UploadPhoto(int thirdPartyID)
{            
    if (!Request.Content.IsMimeMultipartContent())
        throw new Exception(); // divided by zero

    byte[] data = null;
    var filename = string.Empty;

    var provider = new MultipartMemoryStreamProvider();
    Request.Content.ReadAsMultipartAsync(provider).ContinueWith(y =>
    {
        foreach (var file in provider.Contents)
        {
            filename = file.Headers.ContentDisposition.FileName.Trim('\"');
            data = file.ReadAsByteArrayAsync().Result;                            
        }

        var image = this.GetImageFrom(data);            
        var member = this.GetMemberBy(thirdPartyID);

        member.ProfileImage = data; 

        this.memberService.Save();                        
    });           
}

The problem occurs when the following line executes:

this.memberService.Save();

I'm using Ninject and Entity Framework. When this executes I get the error: The ObjectContext instance has been disposed and can no longer be used for operations that require a connection. I'm assuming this is happening because the 'ContinueWith' is executing asynchronously within a different request scope than what my DI has bound the original DbContext? Here is my DI bindings for my UOW:

kernel.Bind<IUnitOfWork>().To<UnitOfWork>().InScope(x => HttpContext.Current);

I've read how to change the DI so its scope is bound to an object, but this is a large project and I'm not comfortable at this stage changing the composition root. Does anyone have a work-around that doesn't involve changing the DI? I tried changing the line

Request.Content.ReadAsMultipartAsync(provider).ContinueWith(y =>...

to run synchronously with

Request.Content.ReadAsMultipartAsync(provider).RunSynchronously();

or

Request.Content.ReadAsMultipartAsync(provider).Wait();

The 'RunSynchronously' method gives me an error, the Wait() method just hangs. I just need to upload an image then store it in the database.

EDIT Just came acorss this: Request.Content.ReadAsMultipartAsync never returns. I updated my code based on that post and it fixed my problem!