After each suscessful order, by which I mean there are no apparent errors or issues with the order to the user. Upon trying to log into the site right afterwards an error is thrown. This seems to also be associated with a problem I am seeing were the client is receiving 3 emailed invoices for every order placed. Error text to follow.

AssemblyVersion: 5.4.0
PortalID: 0
PortalName: Heritage Archivers
UserID: -1
UserName:
ActiveTabID: 76
ActiveTabName: Home
RawURL: /Home.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: http://www.heritagearchivers.com/LoginPage/tabid/85/Default.aspx?returnurl=%2fsupport.aspx
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 ( .NET CLR 3.5.30729)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 2389db5a-1d38-4f3f-8cc5-86d4b5f61f2f
InnerException: Unhandled Error:
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Number.StringToNumber
StackTrace:
Message: System.Exception: Unhandled Error: ---> System.FormatException: 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 System.Convert.ToInt32(String value) at DotNetNuke.HttpModules.Membership.MembershipModule.OnAuthenticateRequest(Object s, EventArgs e) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) --- End of inner exception stack trace ---
Source:
Server Name: WEB24