Here's the scenario:

1. I add the Feedback module to a page on the first portal.
2. A user leaves feedback.
3. I add the feedback module to a page on the second portal.
4. The feedback from the first portal is shown on the second.

vitkoz: your link doesn't work, and maybe you would be kind to say how you fixed it, or what you think should be a new way of doing the category management.  Always interested in ideas.

Everyone: When the feedback module was revamped last year, i made the choice to use the lists functionality.  It seemed to be an apppropriate match, becuase at the time it seemed redundant to make a categorization system for feedback categories.  but the lists functionality was quite new at that time, and i did not realize the data leakage issue between portals.  So we are working on a new version that will fix that issue and will keep you updated.