Finally resolution.

Today I went to another tire shop and asked them to check my tyres if they had been balanced correctly. YES YES YES!!!!, 3 tyres where un-balanced. Funny, since I had re-balanced them 3 times at the largest tyre shop in town. Consequently, I went back
and reclaimed my money .

Now my W210 goes like it use to. That is, stedy as rock regardless of the speed.

//Dimitris

Dimmi,

Naturally, the original tyre place will have it's balancing equipment re-calibrated immediately and turn away balancing work in the mean time...............

__________________
Paul Gibbons
'93 320CE
'73 Jensen Interceptor (Resting)
Giant Full Sus Mountain Bike

One would like to think that…same probability, as I will return to them as a costumer

Dimmi,
Don't feel like you have been screwed. I talked my tire man about balancing and he said that he can balance a tire, put it on the car, take it back off without even running the tire on the ground, and it will show that it needs to be balanced again. He said that any balance is just an average and that the machines are so sensitive that there really isn't any perfect balance.

Balancing a tire is not rocket since. More over, if that the result of the balancing process will result in an “average” weight on the tires does not change the fact. That is, if the resulting weights are average weights, the variance of those weighs should be within a given margin. This margin should at least ensure that the car do not produce any shake on the steering wheel.
Failing to do so 3 times in a row smells like a systematic error somewhere. That is, the equipment is not calibrated or the staff employing it is not really capable of handling such equipment.
And Yes ! They do exist i.e. the “perfect balance ” I just got one...