I am writing an enterprise application which will have several dozen 'modules'. The menu bar is used for several purposes.
When a user selects a module, such as Inventory Maintenance, the Actions Menu and Functions menu need to be populated with items which are relevent for that particular module. In some cases, the menu item may need to be disabled based on where the user is or what they are doing (this was the disabled issue which you already answered)
I hope this answers your question.