Here's my situation:

Website with two languages, containing a webpage that's already localized (by the button 'ready for translation'.)
In the webpage there's a HTML-module and a Document-module. The Document-module works perfectly, when I add a new document, it's available in both languages. And with the HTML-module I can give an introduction in both languages.

But now I want to add another download-section, thus another HTML- and Document-module. Both should be localized as well, I don't want two different modules in each language. (Double maintenance)

Question 1: What's the correct procedure for this?
My guess would be that after I've added both modules to the default language, I should press the "Ready for translation"-button again.

Question 2: What's going wrong when my solution mentioned above is correct?
When I click "Ready for translation" I get a JavaScript-error. And nothing happens, so the modules don't appear on the second language-page.

InnerException: Sequence contains more than one element
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Linq.Enumerable.SingleOrDefault
StackTrace:
Message: DotNetNuke.Services.Exceptions.PageLoadException: Sequence contains more than one element ---> System.InvalidOperationException: Sequence contains more than one element at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source) at DotNetNuke.Entities.Modules.ModuleController.AddModulePermission(ModuleInfo& objModule, Int32 portalId, String roleName, PermissionInfo permission, String permissionKey) at DotNetNuke.Entities.Modules.ModuleController.LocalizeModuleInternal(ModuleInfo sourceModule) at DotNetNuke.Entities.Modules.ModuleController.LocalizeModule(ModuleInfo sourceModule, Locale locale) at DotNetNuke.Modules.Admin.Tabs.ManageTabs.readyForTranslationButton_Click(Object sender, EventArgs e) at DotNetNuke.UI.WebControls.CommandButton.OnButtonClick(EventArgs e) at DotNetNuke.UI.WebControls.CommandButton.RaiseClick(Object sender, EventArgs e) at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs 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) --- End of inner exception stack trace ---