Your track ir is not returning to its center position. There are certain short cut keys linked to track ir. For example, pause and center etc. The keys should not overlap with dcs otherwise whenever u press those keys in dcs the track ir will be effected.
Secondly, if u are wearing glasses in that case u have to put the track ir at a certain distance and angle other wise reflection from glasses will make track ir go mad.
thirdly, sunlight in the back ground will also effect the trackir.