I am a huge fan of Google Analytics, but even so, you should be aware of several bugs that have been confirmed by Google.
(1) A Google Groups thread confirms that some users are unable to login to Google Analytics, due to a "Redirect Loop." The error message continues to say, "Firefox has detected that the server is redirecting the request for this address in a way that will never complete...".
There errors began to be reported on July 7th. Last night, a Google representative replied saying:
Thanks for your patience while our technical team works to resolve this issue. They are aware of the redirect error that occurs with some users when they try to log in to their Analytics account. While we work towards a long term solution, please visit the following URL and create a new account using the same login email:
(2) Google Analytics has been reporting to some users that their tracking code is not installed. But the reality of it is, the tracking code for those sites are installed properly and Google Analytics is actually tracking data and reporting on that data. So the message is incorrect and the tracking code for some of these sites are indeed installed correctly. I actually have this on one client's site, and I can personally confirm it.
A Google representative confirmed the issue in a Google Groups thread:
As some of you have mentioned, there is currently a technical issue with the tracking code status indicator. Even after you install the Analytics tracking code on your site and receive data, you may see a "Tracking Not Installed" error next to the profile in question. If you see data in your reports, you may disregard this error while our technical team investigates.
(3) Google Analytics is duplicating the cities information in the Map Overlay reports for some users. A Google Groups thread has a picture of what this may look like for you:
A Google representative confirmed the issue:
Thanks for bringing this to our attention. Our technical team is aware of this issue, where duplicate entries for a city can appear in the Map Overlay report. For now we have enough information to investigate. In the meantime, thanks for being patient!
There are three bugs that have been recently confirmed by Google Analytics that you should be aware of.