The X5 will never handle like the 740i. The weight and center of gravity are much higher in the X5.

That being said the only time I have had the ABS kick in on either my '01 or '06 has been on a wet road when trying to put my brake pedal to the floor as to not run over the top of a Miata that tried to make a left turn from the right lane.

As for the DSC, I tried to do donuts in the dirt with the '01 and couldn't until I turned off the DSC.

So in other words, I think something IS going on. Most likely a wheel speed sensor.

__________________
0O(llll)(llll)O0
2007 Suzuki Vinson 500 4X4
2007 Toro 6.5hp
2006 BMW X5 4.4 ltr (his)
2001 BMW X5 4.4 ltr (hers)
1994 Honda XR650L
1984 Honda XR80

"Beer is proof that God loves us and wants us to be happy."
Benjamin Franklin