Do you mean like, when you're driving on the far left/far right lane and it begins to split into two lanes with the leftmost/rightmost lane being an HOV lane, then DDP starts merging you into the HOV lane? If that's your issue with DDP, I'd say that happens to me about 10 - 40% of the time I have DDP on while an HOV lane "emerges" (I'm not exactly sure of the numbers, since I'm not keeping track; but it's definitely happening less than half of the time).
Whenever this happens, I just jerk the steering wheel to get me back into the proper lane. It only takes a second or two for DDP to take back control and we go our merry way. If this is what you're experiencing, I believe this is normal behavior and is indicative of DPP being a work-in-progress that could use further tweaking.
If you have a different issue, can you explain more precisely what problem you're experiencing?