Custom AppDomain and PrivateBinPath

I'm using c# 4.0 and a console application just for testing, the following code does gives an exception.

AppDomainSetup appSetup = new AppDomainSetup()
{
    ApplicationName = "PluginsDomain",
    ApplicationBase = AppDomain.CurrentDomain.BaseDirectory,
    PrivateBinPath = @"Plugins",
    ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile
};

AppDomain appDomain = AppDomain.CreateDomain("PluginsDomain", null, appSetup);

AssemblyName assemblyName = AssemblyName.GetAssemblyName(System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Plugins", "sample.dll"));

Assembly assembly = appDomain.Load(assemblyName); //This gives an exception of File not found

AppDomain.Unload(appDomain);

I keep getting File not found exception when using Load on my created AppDomain.

Thanks.