AbleCommerce Shopping Cart Software

I havent had a problem reported to me, but I have about 4 of these errors within a 30 min period in our log. Can someone advise what may be wrong or if there is something I should test and investigate.

An error has occured at http://www.siteroot.com/Members/MyWishlist.aspx
Exception: Exception of type 'System.Web.HttpUnhandledException' was thrown. Stack Trace: at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.members_mywishlist_aspx.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) Inner Exception: Exception has been thrown by the target of an invocation. Inner Exception Stack Trace: at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at CommerceBuilder.DomainModel.EntityWithTypedId`1.Delete() at CommerceBuilder.DomainModel.PersistentBag`1.DeleteAt(Int32 index) at AbleCommerce.Members.MyWishlist.WishlistGrid_RowCommand(Object sender, GridViewCommandEventArgs e) at System.Web.UI.WebControls.GridView.OnRowCommand(GridViewCommandEventArgs e) at System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) at System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) at System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) at System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) Inner Exception: Exception has been thrown by the target of an invocation. Inner Exception Stack Trace: at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at CommerceBuilder.DomainModel.EntityWithTypedId`1.Delete() at CommerceBuilder.DomainModel.PersistentBag`1.DeleteAt(Int32 index) at AbleCommerce.Members.MyWishlist.WishlistGrid_RowCommand(Object sender, GridViewCommandEventArgs e) at System.Web.UI.WebControls.GridView.OnRowCommand(GridViewCommandEventArgs e) at System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) at System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) at System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) at System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

From the error message, it seems that someone has tried to delete an item from wishlist that caused this exception for some reason. You can attach a breakpoint at protected void WishlistGrid_RowCommand() method to debug and see why this has happened.