Hi I'm trying to implement CdLoader in Umbraco 6 and when I add the CdLoader Marco to a page with Debug = false the marco errors with the following error.

ArgumentNullException was unhandeled

Value cannot be null.
Parameter name: virtualPath

It's at the following stage in the file:

renderer.RegisterDependencies(allDependencies, paths, out jsOutput, out cssOutput, Context);

The full razor file cobeled together from a few form posts

@*
    This class will help you to load all scripts and stylesheets using ClientDependency
    Parameters:
    CssPaths (string) Pipe-separated css. The order how you put them is important
        LessPaths (string) Pipe-separated less. The order how you put them is important
    JsPaths (string) Pipe-separated js
    IncludeDefaultPaths (bool, default false) If true, it will prepend ~/css, ~/less and ~/scripts
*@
@inherits umbraco.MacroEngines.DynamicNodeContext
@using ClientDependency.Core
@using ClientDependency.Core.Controls
@{
    var cssPaths = Parameter.CssPaths;
    var lessPaths = Parameter.LessPaths;
    var jsPaths = Parameter.JsPaths;
    bool includeDefaultPaths;
    bool.TryParse(Parameter.IncludeDefaultPaths, out includeDefaultPaths);
    CdObjects cdPaths = GetClientDependencyPaths(cssPaths, lessPaths, jsPaths, includeDefaultPaths);
    @Html.Raw(cdPaths.Styles)
    @Html.Raw(cdPaths.Scripts)
}
@functions 
{
    CdObjects GetClientDependencyPaths(string cssPaths, string lessPaths, string jsPaths, bool includeDefaultPaths)
    {
        var paths = new HashSet<IClientDependencyPath>
        {
            new ClientDependencyPath {Name = "Styles", Path = "~/css"}, 
            new ClientDependencyPath {Name = "Less", Path = "~/less"}, 
            new ClientDependencyPath {Name = "Scripts", Path = "~/scripts"}
        };
        var allDependencies = new List<IClientDependencyFile>();
        string cssOutput = "";
        string jsOutput = "";
        int priority = 0;
        if (!string.IsNullOrEmpty(cssPaths))
        {
            allDependencies.AddRange(cssPaths.Split('|').Select(path => new CssInclude { PathNameAlias = includeDefaultPaths ? "Styles" : string.Empty, FilePath = path, Priority = priority++ }));
        }
        if (!string.IsNullOrEmpty(lessPaths))
        {
            allDependencies.AddRange(lessPaths.Split('|').Select(path => new CssInclude { PathNameAlias = includeDefaultPaths ? "Less" : string.Empty, FilePath = path, Priority = priority++ }));
        }
        if (!string.IsNullOrEmpty(jsPaths))
        {
            priority = 0;
            allDependencies.AddRange(jsPaths.Split('|').Select(path => new JsInclude { PathNameAlias = includeDefaultPaths ? "Scripts" : string.Empty, FilePath = path, Priority = priority++ }));
        }
        var renderer = new ClientDependency.Core.FileRegistration.Providers.StandardRenderer();
        renderer.RegisterDependencies(allDependencies, paths, out jsOutput, out cssOutput, Context);
        return new CdObjects { Styles = cssOutput, Scripts = jsOutput };
    }
    class CdObjects
    {
        public string Styles { get; set; }
        public string Scripts { get; set; }
    }
}

Any ideas as to why it's unable to output the files correctly?