The comments are'nt copying over from one page to another. The comments being displayed are ALL the comments that have been saved for the feedback module. As such, this would show up irrespective of which page and how many instances of the feedback module you're using.
However, to answer your question, this is why categories were created - you can create a category, assign it to the feedback instance on a specific page and then set the view comments to load only that category. This could then be applied to other instances of the feedback module too - this would effectively limit what shows up in the view comments piece...

Sanjay