I just analyzed in wireshark, some of the packets I captured with airodump-ng. And contrary to one of the tutorials I've read on aircrack's website (How to crack wireless via a wireless client) I can't see any 68 or 86 bytes in length packages coming from or going to the AP, even if there's a wireless client connected, one of my laptops.

Something is very weird, no wonder I couldn't inject anything back.

If someone has an idea of what I should tweak, please let me know!