FVS336Gv2 dropping DNS packets >512 bytes

Hello,
I finally had an opportunity to put the FVS336Gv2 back as our network edge router and tried your suggestion. Unfortunately, I am seeing the same results. I noticed a new firmware version posted so I upgraded firmware and tried again, with the same results. Firmware was upgraded by reseting to factory defaults, upgrading firmware, reseting to factory defaults, and reentering configuration manually. I have also tried forcing Bind to use port 53 by editing named.conf to uncomment the line

query-source address * port 53

/*

* If there is a firewall between you and nameservers you want
* to talk to, you might need to uncomment the query-source
* directive below. Previous versions of BIND always asked
* questions using port 53, but BIND 8.1 uses an unprivileged
* port by default.
*/
// query-source address * port 53;

Here are the DNS server logs from a recent DNS lookup:

27-Apr-2011 19:10:05.563 createfetch: www.nytimes.com A
27-Apr-2011 19:10:10.563 createfetch: www.nytimes.com A
27-Apr-2011 19:10:10.699 host unreachable resolving 'www.nytimes.com/A/IN': 2001:503:231d::2:30#53
27-Apr-2011 19:10:15.563 createfetch: www.nytimes.com A
27-Apr-2011 19:10:21.668 host unreachable resolving 'www.nytimes.com/A/IN': 2001:503:a83e::2:30#53
27-Apr-2011 19:10:24.520 success resolving 'www.nytimes.com/A' (in 'com'?) after disabling EDNS

And corresponding FVS336Gv2 logs for same request:

2011 Apr 27 19:10:25 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.55.83.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:24 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.52.178.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:23 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.31.80.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:22 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.26.92.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:21 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.43.172.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:20 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.42.93.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:19 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.54.112.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:19 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.41.162.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:18 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.48.79.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:17 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.12.94.30 PROTO=UDP SPT=53 DPT=53
2011 Apr 27 19:10:16 [FVS336GV2] [kernel] LAN2WAN[ACCEPT] IN=LAN OUT=WAN SRC=172.16.53.10 DST=192.35.51.30 PROTO=UDP SPT=53 DPT=53

Any other suggestions?