I have submitted this same issue to DrayTek technical support, but I thought I'd mention it here too in case someone else has seen something similar before.

I have just installed a brand new 2820Vn and am experiencing some strange problems when attempting to connect a Dell Latitude D600 laptop with Broadcom BCM4309 to it over 802.11g and WPA2/PSK. Two other devices (a Dell D630 and Nokia N810) both work perfectly when connected wirelessly.

I have a separate DHCP server connected to one of the wired ports of the router, therefore I have disabled the 2820Vn's DHCP service. The D600 with Broadcom wireless chip successfully associates with the WLAN and receives the correct IP address, subnet mask, router IP, and nameserver settings from the external DHCP server, proving that it is communicating correctly with another device connected to the 2820Vn.

However at this point, the D600 only receives ethernet broadcast packets from the 2820Vn and other devices attached to it (such as ARP requests, STP packets from a Netgear switch on the same segment, etc.) It does not receive any unicast packets such as ARP replies, therefore is unable to use the WLAN for anything useful. This has been determined by using the wireshark network sniffer and protocol analyzer software. The laptop's firewall has been disabled.

I see the same symptoms with the stock 3.2.1 firmware as with 3.3.0 and 3.3.2_RC1. The D600 has worked fine on several other wireless networks, including a WPA2/PSK network provided by the Linksys WAG54GX2 which the 2820Vn is replacing.

I only set up a single SSID, and I have not enabled any kind of member or LAN isolation at all.

I would greatly appreciate some advice on things I could try to determine the root cause of this problem. Thanks!