jQuery Grid Plugin - jqGrid

I'm currently trying jqGrid with .netTiers. Whenever I bind any data to a grid I'm getting a “Parameter count mismatch” error. I'm using the Northwind database and doing something simple like this:

grid.DataSource = DataRepository.CategoriesProvider.GetAll().ToArray();

grid.DataBind();

I also tried using the datasourceobject with no luck.

Here's the stack trace

[TargetParameterCountException: Parameter count mismatch.]
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +7520150
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +29
   System.Reflection.RuntimePropertyInfo.GetValue(Object obj, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture) +53
   System.Reflection.RuntimePropertyInfo.GetValue(Object obj, Object[] index) +20
   Trirand.Web.UI.WebControls.JQGrid.ObtainDataTableFromIEnumerable(IEnumerable ien) +588
   Trirand.Web.UI.WebControls.JQGrid.GetDataTableFromIEnumerable(IEnumerable en) +124
   Trirand.Web.UI.WebControls.JQGrid.PerformRequestData(IEnumerable retrievedData) +611
   Trirand.Web.UI.WebControls.JQGrid.OnDataSourceViewSelectCallback(IEnumerable retrievedData) +115
   System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +31
   Trirand.Web.UI.WebControls.JQGrid.ProcessCallBack() +971
   Trirand.Web.UI.WebControls.JQGrid.OnPreRender(EventArgs e) +89
   System.Web.UI.Control.PreRenderRecursiveInternal() +80
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842