I've just got an ATC 2000 from an ebay shop (new) and having tried it for the first time I got the following problems: The sound is diabolical - hardly picks up any proper sound at all (i.e. me shouting next to it in a quiet room barely registers). BUT, there is a really loud distorted noise there all the time when it's mounted on the bike. Not wind noise, but a rough crackling distortion. Also, the brightness of the picture seems to fluctuate from normal to quite dark, where it's hard to make things out properly. The test was 1 hour long and taken on a constantly overcast day (but still quite bright). Anyone had similar problems with one of these?