I used "update-rc.d wicd defaults" to start networking automatically with booting BT4. It works as expected but I would really like to disable it (for the root at least ). How to do that?

Also, I've noticed some weird stuff after using above-mentioned line;
to use aircrack-ng suite, I have to stop dhclient and wpa_supplicant - makes sense, no problem.
BUT, while using default "wlan0" with monitor mode enabled I can no longer use aireplay-ng to associate with my AP. Instead, I have to use mon0 at the end of the line and it works great.
With "wlan0" I can no longer authenticate nor associate at all.

I tried using ifconfig to disable/enable my wlan card and then used aireplay-ng with "wlan0", only to get obnoxious:

Code:
ioctl(SIOCSIWMODE) failed: Device or resource busy

ARP linktype is set to 1 (Ethernet) - expected ARPHRD_IEEE80211,
ARPHRD_IEEE80211_FULL or ARPHRD_IEEE80211_PRISM instead.  Make
sure RFMON is enabled: run 'airmon-ng start wlan0 <#>'
Sysfs injection support was not found either
Again, with "mon0" it works great...
What could be the problem?