On my TV, when the computers shows the windows desktop I get some purple blotches, that slowly disappear.  And at the top left corner of the screen, the image bends in a little bit, and you can see a little bit of colour separation.  Oddly enough when watching TV on it through composite cable, none of this happens.  So my question is.  Is this an issue with S-video or needing to have it degaussed?  I