Page 1 of problem with "Video Signal Conditioner sb-3670" unit

I recently purchased the above signal conditioner box from Maplins with the (obvious) intention of defeatting the Macro protection signals when recording to my Panasonic DVD recorder (E-30)
While the box works in as far as it does allow me to make copies from DVD and video sources, there is a small but noticable problem with "colour smearing" - especially on vivid reds, and a faint sort of thin "line" of colour across the middle of the picture.

Has anyone else encountered this type of problem...and if so could you pass on any tips which may rectify it..?
(I`m probably missing something incredibly simple.......!)