I think that an example is probably the best to explain what's wrong (I have attached screen captures):
adminpage1, adminpage2, etc... show pages 1, 2, etc.. of the results given by the search engine when the site admin looks for the string "histoire".
It works perfectly, each page saying that there are 46 results, the results are displayed like this: 10 on each of the four first pages and 6 on the last one)

Now, if the user is a student (who doesn't have access to most courses), things go really wrong:

studentpage1, 2 and 3 show the pages of results for the same query ("histoire") when I used a student account. The first page tells me that there are 37 results, but displays only one!
Then, if I click on page 2, I'm then told that there are 29 results (where did the other 8 go?), but only two appear on the page.
Finally, if I want to have a look at page 3, the number of results announced is now 19 (?!), but the page displays NONE AT ALL!

So finally the student gets told that there are 37 or 29 or 19 results to his query (depending on the page he's on), but altogether is shown only 3.

I think that 3 is very probably the right number of results this student is allowed to see, but then they should all be on one page and the number of results announced on that page should be 3!