Hello,
I tested a survey using "&newtest=Y". I stoped at the second page, then started the survey. I then used the link without "&newtest=Y" but was sent to the second page and got the message:
"Please use the LimeSurvey navigation buttons or index. It appears you attempted to use the browser back button to re-submit a page."
After a click on okay I answerd the question and clicked on the "next" button. I then came out the welcome page of my survey.
It seems there is a problem to differentiate between normal survey participation and test mode.