I've seen this happen in situations where the Quick Launch had been
manually edited, and hard-coded to a certain URL.
When you go to your list URL http://sitename/lists/listname/
<http://sitename/lists/listname/>
(without typing the aspx file name)
Does it take you to the correct new view name?
If so, then this just means that you're linking directly to the old
default aspx URL somehow.