I am using dnn 6.0.1 and cart 4.6.  When using UPS as a shipper and calculating shipping, If I change from the default first shipping option in the drop down list to any other item in the list I receive the following error:
	 
	AssemblyVersion: 6.0.1
	PortalID: 0
	PortalName: Aromawellness & Crystals
	UserID: 3
	ActiveTabID: 81
	ActiveTabName: Products
	RawURL: /Products/tabid/81/ctl/Cart/mid/428/Default.aspx
	AbsoluteURL: /Default.aspx
	AbsoluteURLReferrer: http://www.aromawellness.net/Products/tabid/81/ctl/Cart/mid/428/Default.aspx
	UserAgent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
	DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
	ExceptionGUID: 4442e27b-a591-4357-bf97-923ae8c1a291
	InnerException: StartIndex cannot be less than zero. Parameter name: startIndex
	FileName:
	FileLineNumber: 0
	FileColumnNumber: 0
	Method: System.String.InternalSubStringWithChecks
	StackTrace:
	Message: DotNetNuke.Services.Exceptions.PageLoadException: StartIndex cannot be less than zero. Parameter name: startIndex ---> System.ArgumentOutOfRangeException: StartIndex cannot be less than zero. Parameter name: startIndex at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy) at Smith.DNN.Modules.BuyNow.Cart.ddlShipRates_SelectedIndexChanged(Object sender, EventArgs e) at System.Web.UI.WebControls.ListControl.OnSelectedIndexChanged(EventArgs e) at System.Web.UI.WebControls.DropDownList.RaisePostDataChangedEvent() at System.Web.UI.WebControls.DropDownList.System.Web.UI.IPostBackDataHandler.RaisePostDataChangedEvent() at System.Web.UI.Page.RaiseChangedEvents() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---
	Source:
	Server Name: GENERIC121