Undeploy: with pages does not work if the Object standard actions are override

[xhiena]

I have several visualforce pages overriding the standard "view", "clone","new" actions.
When cleaning the Visualforce pages it fails because the page is referenced in the action:

pages/QuoteDetail.page -- Error: You can't change the standard controller object QuoteLineItem because this page is referenced in the action override View.

It happens with standard and custom objects:

pages/invoicedetail.page -- Error: You can't change the standard controller object Invoice__c because this page is referenced in the action override View.

It also fails with extension classes (classes created to extend the controllers of a visualforce page):

classes/CountryRegionExtension.cls -- Error: The method object (ApexPages.StandardController) is referenced by Visualforce Page (CountryRegionMap) in salesforce.com. Remove the usage and try again. (line 5, column 12)