Thanks for replying, mate.
Sorry, I forgot to update this thread, but I've fixed it.
It seems that there's an issue with the current kernel (and as bugs trackers say, the past two kernels too), because it loads two modules in different order, in my network card's case. Therefore, it was necessary to remove one, add the other one and add again the last one, but it works now. Phew.
These being said, I'll mark the thread as 'solved'.
For those seeking an answer here, the network card was a Broadcom type, and the commands I used were:
modprobe -r tg3
I haven't checked if the wireless connection works, but that's a different fish food.