i've also installed it on a 1.5.9 site, when i try to access the old administration page, i get redirect loop error and is not sending the user back to the index page of my site as i declared. Logging of the administration site, i also get a redirect loop error. When i try again to access the administration page a second time around, i do get the old administration page.
The plugin works fine when i use it to access the administration with the key, but why would it still show my old administration page?
* the actual error is:
This webpage has a redirect loop.
The webpage at
www.xxxxxx.com/administrator/ has resulted in too many redirects. Clearing your cookies for this site may fix the problem. If not, it is possibly a server configuration issue and not a problem with your computer.
Here are some suggestions:
Reload this web page later.
Learn more about this problem.
More information on this error