v1.8 Not Displaying Product Details

Hey All - just installed v1.8 on own server running server 2008, .net 4, sql express 2005 sp1 - installation went perfect no glitches and everything worked.....until... I deleted the sample products, categories and manufacturers etc to add new products and now the product details page will not display just getting:

Server Error in '/' Application.
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Value cannot be null.
Parameter name: virtualPath
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.ArgumentNullException: Value cannot be null.
Parameter name: virtualPath

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:


[ArgumentNullException: Value cannot be null.
Parameter name: virtualPath]
   System.Web.VirtualPath.Create(String virtualPath, VirtualPathOptions options) +8829308
   System.Web.UI.TemplateControl.LoadControl(String virtualPath) +17
   NopSolutions.NopCommerce.Web.ProductPage.CreateChildControlsTree() +315
   NopSolutions.NopCommerce.Web.ProductPage.OnInit(EventArgs e) +47
   System.Web.UI.Control.InitRecursive(Control namingContainer) +140
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +480




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



Just wanted to know if anyone else has had this?

Regards
Rob