It should be NSMidY(cellFrame)-(iconSize.height/2.0f), not NSMidY(cellFrame)-(iconSize.width/2.0f),
It works at the moment because iconSize is square (16x16), but if you change the width of the icons then they are drawn above the row the correspond to.
On line 432 in PXSourceList.m: https://github.com/Perspx/PXSourceList/blob/master/PXSourceList/PXSourceList.m#L432
It should be
NSMidY(cellFrame)-(iconSize.height/2.0f),
notNSMidY(cellFrame)-(iconSize.width/2.0f),
It works at the moment because iconSize is square (16x16), but if you change the width of the icons then they are drawn above the row the correspond to.