RFID3 API - Tag reading weird behaviour



I'm using RFID3 API to read a tag's EPC with a FX9500 reader (only one antenna attached). The way I'm doing so is through the TagAccess's ReadEvent and GetReadTags operations (see C# code below)...


  ReadAccessParams rap = new ReadAccessParams();
  this.Reader.Actions.TagAccess.ReadEvent(rap, null, null);
  TagData[] readTags = this.Reader.Actions.GetReadTags(100);


...what I've observed so far is that every tag that gets read successfully apears twice in "readTags" array.


Is it the expected behaviour, or is it a bug?
If this is normal, how can I avoid having each tag reported twice in readTags array?


I've noticed the same occurs if I subscribe to "ReadNotify" event, since every time ReadEvent is called, two events with exactly the same data arrive for each tag in range.