Drift (sort of) - why is it that Protestants tend to talk of "the Lord's Prayer", whereas Catholics use the term "the Our Father"?

It's not as trivial a point as it might sound. I was reading on a site somewhere - I can't remember if it was a Jewish site or an Islamic one - and there was a discussion about whether the prayer was one which could be shared between the faiths. And the main stumbling block seemed to be nothing whatsoever to do with the content, but rather with it being introduced as "the Lord's Prayer", with it's built in assumption that all present shared a common belief about "the Lord".