Well, after 2 weeks of troubleshooting, here's what I came up with;

- On the first picture above, you can see that the cable of the FD goes into a rubber housing, then onto the plastic part attached to the frame. I rode 2 times in the wet, and the rubber housing in which the cable slides caught some water + dirt; this completely increased friction whithin the cable housing.
I removed the cable, cleaned and greased everything and all came back to normal, even though the cable movement is not as silky smooth as described by xdrmusclex.

- Also, which is even more surprising: the design of the FD shifting is so that when you push the lever to go on the big chainring, there is a mechanism where the FD sort of clicks into its outer position. The trick is, if the FD cable is too tight, the FD won't engage (or click into position); it will just put the chain on the outer ring, and return towards the BB, sticking onto the chain.
Loosen the FD cable and shifting becomes perfect.

This is no where written!

Anyway, all sorted now, except for my personal doubts about the design and distortion of the FD cable under the BB shell. A more straight routing would have been smoother, design-wise.