Ive just installed and I keep getting this error when visiting a category page.
Every other page works just fine, even the single product page and administration.
Ive changed the Write options in my IIS.
Is there anything else I can do?

Here is the error message:
______________________________________

Server Error in '/' Application.
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
   NopSolutions.NopCommerce.Web.Modules.ProductBox1Control.BindData() in F:\Own\nopDownloads\downloads\nopCommerce_1.80_Source\NopCommerceStore\Modules\ProductBox1.ascx.cs:76
   NopSolutions.NopCommerce.Web.Modules.ProductBox1Control.DataBind() in F:\Own\nopDownloads\downloads\nopCommerce_1.80_Source\NopCommerceStore\Modules\ProductBox1.ascx.cs:49
   System.Web.UI.Control.DataBindChildren() +201
   System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) +101
   System.Web.UI.Control.DataBind() +15
   System.Web.UI.WebControls.DataList.CreateItem(Int32 itemIndex, ListItemType itemType, Boolean dataBind, Object dataItem) +137
   System.Web.UI.WebControls.DataList.CreateControlHierarchy(Boolean useDataSource) +488
   System.Web.UI.WebControls.BaseDataList.OnDataBinding(EventArgs e) +64
   System.Web.UI.WebControls.BaseDataList.DataBind() +55
   NopSolutions.NopCommerce.Web.Templates.Categories.ProductsInGrid.BindData() in F:\Own\nopDownloads\downloads\nopCommerce_1.80_Source\NopCommerceStore\Templates\Categories\ProductsInGrid.ascx.cs:159
   NopSolutions.NopCommerce.Web.Templates.Categories.ProductsInGrid.Page_Load(Object sender, EventArgs e) in F:\Own\nopDownloads\downloads\nopCommerce_1.80_Source\NopCommerceStore\Templates\Categories\ProductsInGrid.ascx.cs:47
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +91
   System.Web.UI.Control.LoadRecursive() +74
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Control.LoadRecursive() +146
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1