I do.
The thing is, though, I seem to get them only during low detail test renders. For example, I have a scene with 2 populations - one grass, one trees. Test renders above 0.3 detail give no errors, below this(at 0.1 or so for simple testing and placement purposes) throws out an error of something like: Counter error in populator/pop grass clump
The render always looks fine, even with the error, no missing patches of grass in view.
This is with built in TG grass object, I've only seen it with this though, never an imported object.