Upon upgrading to Lion I have found that the laptop will not go into sleep mode when the power cord is plugged in and you shut the lid (clamshell). This is also the case when clamshell to a Cinema Monitor. I can only get it to sleep if I disconnect both the power AND the Monitor and leave the laptop to sleep on its own accord or force sleep. If either are still connected (power/Cinema) it will not sleep on it's own. If I force sleep it, only the monitors turn off but it doesn't go to sleep and it doesn't come out of whatever it is now doing. Anyone else having sleep issues when power (and/or Cinema) is attached? Any suggestions on this issue.