I've searched for other threads, and found some slightly similar, but they were generally lockup that required the battery to be removed. I have an OM-D with the latest 1.5 firmware (had same problem with 1.1? 1.2?) and I use the Pany 14 and 20 and Oly 45mm. I leave the EVF selection to manual and use the EVF almost exclusively for shooting. I have the sleep time set to 1 minute. When the camera goes to sleep, most the time (80%?) it will not wake from sleep with a half-press of the shutter, but occasionally it will. Pushing any other buttons won't wake it either, but cycling the power switch brings it back. Any ideas? It's getting really annoying.