Alignment problem reducing neg camber

[Ranger]

Bought new tires for the X5 so I figured I'd get some of the neg rear camber dialed out. The truck had -1.8 and -2.5 rear camber. Tech had a hard time getting it more neutral. Then he started fooling with the front. Next thing he knew the rear camber had changed to -2.5 and -3.5 deg.

The shop seems to know what they are doing and have the high tech optical laser? computer alignment system.

My truck is an '03 with self leveling Sport Suspension. The computer required us to choose 1 axle or 2 axle air suspension, and also had "sport suspension" as a separate option. We chose 2 axle air suspension. Does that sound correct?

I'd hoped that the shop could get about -1 in the rear. Why do you figure the tech was unable to get this?

I race a BMW 325 so I'm pretty strong on alignment and handling. But I'm not an experienced mechanic. The X5 is my tow vehicle. If the tech says he can't reduce the neg camber any more, I don't have any good ideas to help. The shop is Euro oriented and as a sponsor of my car they've shown themselves to be pretty comfortable with thinking out of the box wrt alignment. I think they are hoping that I'll find a smart guy on the Internet that will know what needs to be done.

Is there anything about the self leveling suspension that makes the alignment process more complex?

Thanks a lot guys.