Having the same issue on Ubuntu Maverick. Xvnc cannot connect to GDM via XDMCP on localhost because of this issue. Exact same config worked fine in Lucid.
Oct 19 10:14:32 leftovers xinetd[1385]: START: Xvnc pid=1930 from=xxx.xxx.xxx.xxx
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: decode_packet: GIOCondition 1
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:1 loopback:1
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmAddress: looking up hostname: leftovers
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=1 protocol=6 flags=0x2 canonname=leftovers#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=2 protocol=17 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=3 protocol=0 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=(null)#012
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: Received opcode QUERY from client ::ffff:ff7f:0:0%1905946208 : 43524
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: Sending WILLING to ::ffff:ff7f:0:0%1905946208
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: decode_packet: GIOCondition 1
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: Received opcode QUERY from client ::ffff:ff7f:0:0%1905946208 : 43524
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: Sending WILLING to ::ffff:ff7f:0:0%1905946208
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: decode_packet: GIOCondition 1
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:1 loopback:1
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmAddress: looking up hostname: leftovers
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=1 protocol=6 flags=0x2 canonname=leftovers#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=2 protocol=17 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=3 protocol=0 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=(null)#012
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: Received opcode QUERY from client ::ffff:ff7f:0:0%1905946208 : 43524
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplayFactory: Sending WILLING to ::ffff:ff7f:0:0%1905946208
Oct 19 10:14:39 leftovers xinetd[1385]: EXIT: Xvnc status=0 pid=1930
Having the same issue on Ubuntu Maverick. Xvnc cannot connect to GDM via XDMCP on localhost because of this issue. Exact same config worked fine in Lucid.
Oct 19 10:14:32 leftovers xinetd[1385]: START: Xvnc pid=1930 from=xxx. xxx.xxx. xxx Factory: decode_packet: GIOCondition 1 leftovers# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 Factory: Received opcode QUERY from client ::ffff: ff7f:0: 0%1905946208 : 43524 Factory: Sending WILLING to ::ffff: ff7f:0: 0%1905946208 Factory: decode_packet: GIOCondition 1 Factory: Received opcode QUERY from client ::ffff: ff7f:0: 0%1905946208 : 43524 Factory: Sending WILLING to ::ffff: ff7f:0: 0%1905946208 Factory: decode_packet: GIOCondition 1 leftovers# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 (null)# 012 Factory: Received opcode QUERY from client ::ffff: ff7f:0: 0%1905946208 : 43524 Factory: Sending WILLING to ::ffff: ff7f:0: 0%1905946208
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:1 loopback:1
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmAddress: looking up hostname: leftovers
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=1 protocol=6 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=2 protocol=17 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=3 protocol=0 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:32 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:34 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:1 loopback:1
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmAddress: looking up hostname: leftovers
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=1 protocol=6 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=2 protocol=17 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=10 sock_type=3 protocol=0 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null) port:(null) local:0 loopback:0
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:38 leftovers gdm-binary[925]: DEBUG(+): GdmXdmcpDisplay
Oct 19 10:14:39 leftovers xinetd[1385]: EXIT: Xvnc status=0 pid=1930