Select -- for all entries.. fetching Duplicates

Hi,

Im using a Select- for all entries structure. Actually Select will supress the Duplicates .But i have a table which has 20000 entries , but my select --for all entries fetching around 56000 records..!

Any idea/ anybody have Experience this kind of Problem..?

If i sort the internal table would it resolve the proble..? Because its not happening in all cases.. but for few cases only its extracting duplicates.. other times..its supressing the duplicates.

Appreciate any advise.