My book live never sleeps

so you verified that the MBL went to sleep if it had media sharing enabled, but the DVR was no connected? 

Some people are finding that even if you have no dnla destinations hooked up, just having media sharing enabled on the MBL will not let it sleep.

Myron is also finding that if you never log off your computer, the quickview status checks may fill up the drive log cache and start writing to disk, preventing sleeping.