Audirvana 3.5. Clicks and pops issue at 0 oversampling

I use Audirvana 3.5 as a player on a 2.23ghz MacMini late2009, 8gb of RAM and 250gb SSD disk completely dedicated to the function of a music machine present on an external 4TB 3.5 hard disk. With some files it happens that if they are played at 0 oversampling they always appear in the same points while listening to the clicks / pops. If, however, I carry out oversampling, the defect disappears. What can it depend on? How can I listen to the same files without oversampling?
Thanks 
Alessandro