BVCommerce 5 Paypal expres error

For anyone that has encountered this error, it was fixed in one of the newer patches. The message on screen is stated below:

Since the site has changed and some forum information has been archived, the link has changed. Here is the new link to the fix:
http://forums.bvcommerce.com/default.aspx?f=81&m=43087



Page.IsValid cannot be called before validation has taken place. It should be queried in the event handler for a control that has CausesValidation=True and initiated the postback, or after a call to Page.Validate.[ at System.Web.UI.Page.get_IsValid() at BVModules_Controls_PaypalExpressCheckoutButton.PaypalImageButton_Click(Object sender, ImageClickEventArgs e) at System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) at System.Web.UI.WebControls.ImageButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.ImageButton.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) ]