ResultsTotalCount different than actual collection size returned
I am using the SOAP api to query a Sitecore index and I am getting occasional discrepancies between the ResultsTotalCount on the return object and the actual size of the result collection returned; i.e. ResultsTotalCount will indicate I have 13 matches, but only 12 results come back from my query. In addition, when I run the exact same query through the Coveo Admin Tool, I receive the correct result set. I have looked at the item that is missing from my sitecore call and nothing immediately jumps out at me as a possible reason for its omission - the item is not a duplicate result, and it has been published through normal workflow. Is there some other field, either in Sitecore or in Coveo that would give any indication as to why this item is excluded?
Thank you very much in advance for any help on this issue!
The duplicate filtering feature can have this effect, but when this happens the TotalCount will go down as results are filtered. One easy way to check this is to request a large number of results. In your case, if you were to request 100 results and receive only 12, the TotalCount should be 12, but if you request only 1 it should be 13. Is that the case?
(duplicates a checked for results that are truly returned for performance reasons).