When using grenade, and casting it over doodads, the grenade seems to 'bounce' off an invisible wall, and the projectile lands somewhere other than where I aimed it. Needless to say this affects where the explosion, damage etc. happens. What gives?
I think this is unavoidable when using the 'Move unit' function. Perhaps you can replace the 'Move unit' with the custom script 'SetUnitX/Y' and see if it helps or not. Otherwise, you'd just have to live with this.