My third DL sat over in the corner of the room with my original iPad in it running audio for the last week week solid. It resynced repeatedly, but always recovered. Seems clear to me that there is something in the communication code that is borderline. Variance in the hardware either slides too far off the edge or doesn't. If you're a lucky one with good hardware, and you don't stare at your DL nonstop, you might well never notice the resyncs. Dialog box pops up for a second and goes away. So, my recommendation is that if you have one that drops sync and doesn't recover, send it back and get one that doesn't.
