The "drag" functionality in CO is very annoying - in most cases when I want to drag&drop some file, the "file select" option kicks in instead.
The "drag" works only if the file is picked up and dragged very vertically, anything over 45 deg from vertical is interpreted as "select"
In the effect 80% times I need to begin "de-selection" of accidentally selected group of files, than carry on with work.
I am not sure if the selection should be at all done this way, but if so - then the angle telling the "drag" and "select" options apart should be larger than 45% (maybe even configurable? It might be a personal preference).