So this is one of those fun things that I can't tell whether the error is the fault of Lion, my MacBook Pro, or iCloud. I tried searching the forums for the same problem and I couldn't find anyone experiencing the exact symptoms as I am. Most (but not every) times when I wake my MacBook up from sleep, or connect to a new Wifi connection I get the following error message: I enter my password, check the "remember this password in my keychain" box, and everything goes on working fine until I put my MacBook to sleep again. The next time I wake it up (or change wireless networks) BAM! same problem. It seems like Mail is trying to verify my iCloud account when there is no Internet connection, because the window usually pops up before I have a network connection established. Any ideas on how to stop this from happening? It's really obnoxious to keep signing in every time I wake my computer up.