I am experiencing fairly strong flickering when I am videoing dark areas with 25 shutter speed (I have a PAL model). The image can be fine if there are no dark areas, but if for examle I film a wall and a black chair in front of it I will notice lines running across that dark area. This only happens when I use batteries and does not happen when I use the power supply from the socket. It happens on 50 shutter speed as well but is not so noticable. Is this supposed to happen does anyone else have this problem?

Are you using this PAL cam in NTSC land?? If you are, the power system here is 60 cycles. PAL is based on 50 cycles. What I do with my PAL cams is not use them in artifical lighting, unless I'm shooting in PALsville.

No I am in Australia we use Pal, the strange thing is that this doesnt happen when I use the power from the socket instead of the battery.

I'd guess that the camera uses the power line frequency to prevent the hetrodyning you experience. When the camera is on batteries, it has no reference and so it free-runs.

I'm talking about the internal clock that the camera uses to count out all of the timing signals required by the camera.