Archived - Mac OS X: Mac may not sleep when using some Bluetooth mice
Certain third-party Bluetooth mice may "sleep" or disconnect if left idle, to conserve battery power. This may prevent your Mac from sleeping. If you try choosing Apple > Sleep, your Mac may sleep for just a moment, then wake soon after.
- Choose Apple > System Preferences.
- Click Bluetooth.
- Click Advanced... in Mac OS X v10.5 or v10.6 or click the Settings tab in Mac OS X v10.4.
- Deselect the "Allow Bluetooth devices to wake this computer" checkbox.
- Click OK.
Alternatively, if you allow the Mac to wake, it will likely go back to sleep after the idle interval specified in its Energy Saver preferences.