Recommend result contains item which user has already given preference, is that correct?

[WangRamon]

Hi Guys I finished running the RecommenderJob today on the two nodes cluster, 
finally. But what suprised me is that the final recommend output of the 
RecommenderJob contains item which user has already given preference, I'm not 
sure is that correct? If it was wrong how can I resolve this problem? Thanks a 
lot. Cheers Ramon