Finder: Limiting entries in "Recent"

I have only recently noticed that the number of files in my Mac and Macbook "Recents" file have become excessive. Seeking advice, I see I should be able to setthe number of entries in "Recent documents, applications and servers" to anywhere between 5 and 50. I currently have 61 in "Recent" on my recently purchased Mac, and 787 on my 2 ½ year old Macbook, plus masses on on all other applications. Why can I not reset the displayed limits? Tried everything I can find, but so far nothing works.