If you use multiple google services (gmail, blogger, adsense, analytics) and different accounts you may have noticed some problems these days:
- when you sign-in to Google Analytics you are presented with your account setup page even if your account was already set (like this account doesn't exists)
- you cannot use two different services at the same time with two different accounts (when you will sign-in for a service the orther will be signed-out)
- you can create more accounts with the same e-mail address and your password will make the difference (strange behavior)
A simple resolution for some of these problems is to delete stored cookies. If you use Firefox you have the option to select what cookies to remove (Tools > Options > Privacy > View cookies... and remove all from gogole). For Internet Explorer (7) you will have to delete all cookies and this is a bit annoying because you will loose some settings from other websites.
A better but more time consuming resolution would be to recreate all your accounts using a single Gmail address and account. For some services (adsense) this is not possible for the moment. I hope Google will present us some best-practices soon.