Alignment issues

[1983/300CD]

The other thread on alignments got this issue back on my mind, so I thought I'd ask for some input from you guys.

When I got my car, it would find the center. I could turn the wheel a little, let go, and it would go straight again. It was great.
With a visual representation, it drove like this "\ /".
(Alright, that isn't technical, but that's how it felt.)

First thing I did was to go to a indie MB "expert" who checked it out and replaced a tie rod because the boot was bad. No problem. Then, they aligned it. Now it doesn't seek the center anymore.
The visual representation of this feeling is like "/ \".
It seems to happily go out of center, and it actually usually drifts left.

The steering box adjustment wasn't touched.

The same exact thing happened with my other car. Also a 300CD, but aligned by a different shop in a different state. Both were aligned using the LASER and computer screen. Is there an "old fashioned" way of doing an alignment?

What is going wrong?
Anybody know of any place on the East coast who gives a good alignment?

Apparently, it's difficult to get a correct alignment on these things. When I first bought mine a "tire shop" really messed it up so it destroyed the tires. I've had good luck with an independent alignment shop in CO. If you can't find a good alignment place, try a dealer.