If the survey is shown group by group, the last group isn't shown (because it's hidden or not relevant) and you want to update the response in the survey ( Allow multiple responses or update responses with one token? is YES), the end message is displayed. So if you open
[limesurvey home]/index.php/survey/index/sid/[surveyid]/token/[token]/lang/en/newtest/Y
you can't return to a question group and editing answers, because there is no way to leave the "end message"-page.

The behaviour in Limesurvey 2.00 was different and in my opinion better:
When you were visiting
[limesurvey home]/index.php/survey/index/sid/[surveyid]/token/[token]/lang/en/newtest/Y
and the token had a response, you saw the "welcome message"-page. From this page, you were able to click through the survey with the entered data and editing the survey.

In 2.05, limesurvey show you the last question group. That's not bad. But if the last question group is hidden, you get to the "end message"-page and that's not good, because you can't edit the responses.