table borders not hiding

Hi,

I'm using CKEditor on one of my sites. All is well, except despite making my border table "o" and setting their color to the same as the background, I still get the table border appearing, only though, across the top and down one side - it's hidden, like I want, everywhere else.

Any suggestions please, to what may be causing this, I read online GP might be adding this by default and I can overcome by entering some CSS, if so, could you please suggest some?

Thank you & Regards,
Robert