First, here's my setup:
ASUS EEE 1000H
WLAN Card (replaced the original): Gigabyte with Atheros chip
OS: BackTrack 3 installed on SDHC, configured for persistent changes
The WLAN card support packet injections, airodump, etc. Tested and can monitor and crack WEP/WPA.
My understanding is that to be able to sniff packet in promiscous mode, I have to enable the WLAN card (ath0) in MONITOR MODE. However, if I do that, I cannot join the wireless network which I tried to sniff. But once I changed ath0 to Managed mode, Wireshark doesn't capture in promiscous mode.
What I want is to test connecting to my WLAN network and then run Wireshark.