Hi all, I've done a bunch of searches and not quite found an answer. I've got a MacBook Pro 3,1 with 4 GB RAM, 240 GB SSD that I recently upgraded to Mavericks from Snow Leopard. Currently running 10.9.2. Sometimes when I close my computer, it doesn't go to sleep mode, sometimes it does. In either case, sometimes when I come back to my computer, it's warm, the fan is running on high, the light on the front is bright and constant, and when I open it, the screen is blank and the light on the front dims and oscillates as if it has just been put in sleep mode. Powering it off is the only way to bring it back on. Per a suggestion in another thread, I reset the SMC. I've also reset the PRAM a few times. In the Energy Saver settings, all checkboxes are unchecked and the computer sleep and display sleep are set to 15 minutes with the power adapter plugged in, which it almost always is. My battery is not in the best condition, even though I've replaced it once. In the Battery tab, computer sleep is set to 15 minutes and display sleep is set to 2 minutes. The dim display checkbox is checked. Any ideas why sleep mode is not functioning correctly? It always did in Snow Leopard... Thanks for any light you all can shed on this!