Here is how to reproduce it:
1. Create an organization, create 4 sub-organization. We need 21 total organization to test this scenario. Since there are already some liferay organizations in the bundle, so creating 5 more would do as created in first two steps.
2. Click on organizations in Administrators left menu control panel items. "Items per Page" is set to "20".
3. It displays "Showing 1 - 20 of 21 results." in top of listings. This is right, no problems till here.
4. Now click on "Next" at the bottom. Now it says "Showing 21 - 21 of 21 results." Now here, is the problem.
I actually see the very same listing of 20 organizations that was shown in page 1. On page 2, it should actually show me only 1 listing of the remaining organization. That 21st organization is not shown in page 2.