ISO-8859-1 and HTML Entities

I am working on a website, I don't know what has changed to cause this problem but in the last few days alot of the HTML Entity characters (&am开发者_如何学编程p;trade; » etc) have had junk characters (™ =â„¢ and » = ») showing in their place. The pages use ISO-8859-1 encoding, In some places the problem can be fixed by forcing the browser to use UTF-8 encoding other times the UTF-8 encoding causes the HTML entites to be replaced by a "�". Any ideas as to why this might be happening and how to fix it. ISO-8859-1 should be able to correctly display html entities.

Your editor is encoding the page as UTF-8 instead of ISO-8859-1 and has converted the entities to UTF-8. Check your editor's settings.