Is it normal that when I launch a search I get the error "Sorry but you cannot use search at this time" clicking on the second results page?
Does the antiflooding system blocks clicks on the results search pages also?
No, is it not possible for users to browse the results of the search. The first page is correctly viewed. When they click on the second one they receive the "Sorry but you cannot use search at this time" message.
They can view the second page only reloading it after the number of seconds (5 seconds) set in the ACP Search settings (antiflooding system).