My N900 can no longer sniff packets in promiscuous mode. It shows the device in promisc from ifconfig and responds perfectly to:

It even shows wlan0 entering and leaving promiscuous mode in dmesg. Despite this I see nothing but broadcast and multicast traffic in tcpdump. A laptop on the same wireless network running wireshark sees all traffic, so it's not a network issue.

I have flashed the device completely several times (except for the eMMC) with no result.

The problem seems identical to the one unanswered here: http://talk.maemo.org/showthread.php?t=70840

Any help? Thanks