Doesn't really matter which file I play (I talk about music files only, btw). Generally after few days of using A2DP, I can tell it gives quite strange behaviours. On day it can play without any interruption for whole journey, the other day it drops out pretty frequently (maybe that was the matter of adapter's battery getting lower?). One thing I've noticed for sure - as long as I'm in the Tube under ground, playback is OK. But once I get out to the surface (especially close to Heathrow Airport where I live), there is a huge increase in number of drop outs. How strange is that?!? Are there any interferences with WiFi networks possible (afaik WiFi and BT use similar radio frequency)? :-o