Hi imageworks,
How are you getting on with this, made any progress?
Although you’re using Structure it shouldn’t affect the return URL at all if a Structure page is setup to handle this. Have you tried the full URL at all? Something like:
return="http://mydomain.com/return"
or you could make it a little more dynamic with:
return="{site_url}return"
Also with the above try with both the www. and without the www. This could be the factor that is different to the last time you did it. Check to see if you’re forcibly removing the subdomain (www) in your htaccess file.
If that doesn’t work do you have any debugging tools which will allow you to see what’s happening underneath? Something like the Live HTTP Headers addon for Firefox would do the job. Make sure redirects are displayed and then we can see if it’s hitting that page at all. If it’s redirecting home then some kind of redirect is working.