Registration problem / bind / udp

Hi there,

after updating to from a very old 1.0.9 i was having problems with asterisk to register to my sip provider. Maybe it works on the first run, but after a reconnect from my ADSL line asterisk cant register.
a tcpdump reveals asterisk is sending udp packets with my OLD IP, not the new one.

Anyways, all local clients connected via the LAN experience the problem that they cant register with the server anymore. tcpdump again reveals the packets are there and good. the clients “timeout”

having debug and verbose enabled on asterisk, leave NO messages. as if asterisk isnt able to send or receive packets after a while. debug level and verbose are 4 or 5.

this problem for instance, happens every time the clients are connected to the pbx for a while. even a “restart now” wont help. ast. has to be stopped and after a couple of minutes started again. then there is a a good chance it works.

Name/username              Host            Dyn Nat ACL Port     Status
sipgate-out/xxxxxxx          N      5060     OK (160 ms)
1001                       (Unspecified)    D   N      0        UNKNOWN
1000/1000               D   N      5060     UNKNOWN

XXX*CLI> sip show registry
Host                            Username       Refresh State                 xxxxxxx            120 Unregistered
XXX*CLI> iax2 show registry
Host                  Username    Perceived             Refresh  State   xxxxxx      88.x.x.x.x:4569            60  Registered

10:16:10.194954 88.x.x.x.sip-ksh >  udp 595
10:16:10.280836 > 88.x.x.x.sip-ksh:  udp 390 (DF) [tos 0x10]

the tcpdump shows packets going out, but wont register.

the firewall setup is correct.

any ideas ?