Thanks again for the answers.
Yes, three weeks already... Before taking action, I am still awaiting the answer from the Bianchi factory. I want to be 100% certain about what I am doing.
With the oil you're right. But I was worried about the breaking cable and I thought that mabe it needed some lubrication in order to prevent it from breaking again. But now I am sure yu're right. From other cyclists I understood that there is a liner inside the hole which functions as a slide bearing. Probably this liner is damaged and caused my cable to break. By taking away the broken cable the damaged liner got jammed in the hole and now it's impossible to put through the new front derailleur cable.
If the above is really the reality, then the old slide bearing will have to be replaced by a new one. I 'll need a new "slide bearing tube" and an instruction sheet (or whatever) from Bianchi in order to know how to mount a new ("slide bearing") tube.
I want to give Bianchi some more time to come up with a sollution. Porbably I am one of the first cyclists with this problem, with many more to follow. After a few years of fanatic cycling the tube will collapse and you've got a major monobox problem .
Edited by BIANCHI_EURO - 4/19/11 at 3:36am