Movement in the front suspension

[Sterling 4.4]

I took the X5 to the local BMW CCA performance track day yesterday and had to call it a short day due to some movement in the drivers side front suspension. It is most noticed when loading the car in a right hand turn. It feels like a something "pops" or moves. When you unload it into a left turn, it "pops" back. I cannot hear the noise due to helmet and exhaust, but my instructor and I could both feel it. It got progressively worse as the day went on and I decided to quit running it on the track for safety reasons. I could not re-create it at slower spreads in the parking lot, but was able to get it to happen again on an on-ramp on the way home.

A fellow X5 world member and I took the wheel off and put a wrench on every bolt we could get too, but nothing was loose.

Has anyone experienced anything ike this? I don't kow much about suspension, but I want to be able to suggest things to the dealer without telling them I was on the track.

My vehicle is an '06 4.4 w/ 18K miles. I do have a Dinan camber plate installed, but the movement feels like it is happenin much lower in the suspension.