What do you mean by I check in the Terminal?
What check you did?
Check with the Console and Activity Monitor, messages/logs of things running and what is actually running.
I checked the terminal using this.
pmset -g assertions
Nothing is preventing sleep.
Im not sure what exactly im looking for but im running only the activity monitor and firefox and this is what im showing.
4/15/12 12:31:02.349 PM com.apple.usbmuxd: _SendAttachNotification (thread 0x1012fc960): sending attach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _GetAddrInfoReplyReceivedCallback matched.
4/15/12 12:31:02.806 PM usbmuxd: _AMDeviceConnectByAddressAndPort (thread 0x102f81000): IPv4
4/15/12 12:31:21.451 PM com.apple.usbmuxd: _SendDetachNotification (thread 0x1012fc960): sending detach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _BrowseReplyReceivedCallback got bonjour removal.
4/15/12 12:31:32.020 PM com.apple.usbmuxd: _SendAttachNotification (thread 0x1012fc960): sending attach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _GetAddrInfoReplyReceivedCallback matched.
4/15/12 12:31:32.830 PM usbmuxd: _AMDeviceConnectByAddressAndPort (thread 0x102f81000): IPv4
4/15/12 12:32:15.904 PM com.apple.usbmuxd: _SendDetachNotification (thread 0x1012fc960): sending detach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _BrowseReplyReceivedCallback got bonjour removal.
4/15/12 12:32:22.997 PM com.apple.usbmuxd: _SendAttachNotification (thread 0x1012fc960): sending attach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _GetAddrInfoReplyReceivedCallback matched.
4/15/12 12:32:23.446 PM usbmuxd: _AMDeviceConnectByAddressAndPort (thread 0x104181000): IPv4
4/15/12 12:33:06.782 PM com.apple.usbmuxd: _SendDetachNotification (thread 0x1012fc960): sending detach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _BrowseReplyReceivedCallback got bonjour removal.
4/15/12 12:33:19.294 PM com.apple.usbmuxd: _SendAttachNotification (thread 0x1012fc960): sending attach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _GetAddrInfoReplyReceivedCallback matched.
4/15/12 12:33:19.545 PM usbmuxd: _AMDeviceConnectByAddressAndPort (thread 0x102f81000): IPv4
4/15/12 12:33:55.302 PM com.apple.usbmuxd: _SendDetachNotification (thread 0x1012fc960): sending detach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _BrowseReplyReceivedCallback got bonjour removal.
4/15/12 12:34:47.735 PM com.apple.usbmuxd: _SendAttachNotification (thread 0x1012fc960): sending attach for device b8:17:c2:2f:0c:69@fe80::ba17:c2ff:fe2f:c69._apple-mobdev._tcp.local.: _GetAddrInfoReplyReceivedCallback matched.
4/15/12 12:34:48.778 PM usbmuxd: _AMDeviceConnectByAddressAndPort (thread 0x102f81000): IPv4
NOT REALLY SURE WHAT THIS USBMUXD STUFF IS.