Hi

I have a problem after upgrading from version 1.3.4 to version 1.4.5.

A user can no longer subscribe to the newsletter. If i enter an email and click "subscribe" i get the following error:

Error Loading Razor Script (file: Newsletter Subscribe) Input string was not in a correct format.    at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
  at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
  at CallSite.Target(Closure , CallSite , Type , Object )
  at System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)
  at ASP._Page_macroScripts_NewsletterSubscribe_cshtml.Execute() in c:....\macroScripts\NewsletterSubscribe.cshtml:line 27
  at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
  at System.Web.WebPages.WebPage.ExecutePageHierarchy()
  at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
  at umbraco.MacroEngines.RazorMacroEngine.ExecuteRazor(MacroModel macro, INode currentPage)
  at umbraco.MacroEngines.RazorMacroEngine.Execute(MacroModel macro, INode currentPage)

I think it's this line that fails:

Int32 subscriptionId = (Parameter.SubscriptionId != null) ? Convert.ToInt32(Parameter.SubscriptionId) : 0;