I was shooting a dance show yesterday with my EM1 with the battery grip attached. The battery in the grip was quite depleted, but the one in the camera was fresh. I'm not sure if this is relevant but after a while the PBH battery warning light was flashing orange. I assumed it would cut out at some time and switch to the camera battery. Maybe this is not relevant anyway to what happened next ... I found I could no longer release the shutter, and the "writing to card" warning was flashing permanently. Even after I turned off the camera it was still flashing (I mean I was unable to turn off) and I had to remove the camera battery to restart the camera. When I got home I found that I'd lost the last 15 min of shots, even from a time the camera seemed to be working OK. Does any of this ring any bells? Maybe it was just "one of those things" but my confidence in using the camera for mission-critical work is now shaken!!