From: Zi Ree
This error doesn't look like a 64 bit issue but rather like a network problem. The DNS system is responsible to convert network addresses like "secondlife.com" into their respective IP addresses, and this is independant of the Second Life client.
You can never be sure in closed source software

Although I am willing to agree with you.
On the other hand - it looks like sth is broken in client. I can succesfuly resolve all known (from log) names to proper IP addresses on the box I run the secondlife.
2007-01-08T22:57:01Z INFO: Resolving Agni userserver domain name userserver.agni.lindenlab.com
2007-01-08T22:57:02Z INFO: ...Userserver resolved to 66.150.244.151:12036
The client resolved the name succesfully.
Some microseconds later:
2007-01-08T22:57:02Z ALERT: LLXMLRPCTransaction CURL error 6: Couldn't resolve host 'login.agni.lindenlab.com'
but:
arturcz@szczaw:~$ host login.agni.lindenlab.com
login.agni.lindenlab.com has address 66.150.244.120
login.agni.lindenlab.com has address 66.150.244.121
login.agni.lindenlab.com has address 66.150.244.156
login.agni.lindenlab.com has address 66.150.244.160
login.agni.lindenlab.com has address 66.150.244.165
If anyone is interested there is some longer exempt from logfile:
2007-01-08T22:57:01Z INFO: Resolving Agni userserver domain name userserver.agni.lindenlab.com
2007-01-08T22:57:02Z INFO: ...Userserver resolved to 66.150.244.151:12036
2007-01-08T22:57:02Z INFO: LLCircuit::addCircuitData for 66.150.244.151:12036
2007-01-08T22:57:02Z INFO: Verifying message template...
2007-01-08T22:57:02Z INFO: Message template is current!
2007-01-08T22:57:02Z INFO: LLMessageSystem::disableCircuit for 66.150.244.151:12036
2007-01-08T22:57:02Z INFO: LLCircuit::removeCircuitData for 66.150.244.151:12036
2007-01-08T22:57:02Z INFO: Authenticating: Arthur Fapp,
2007-01-08T22:57:02Z INFO: Options: inventory-root, inventory-skeleton, inventory-lib-root, inventory-lib-owner, inventory-skel-lib, initial-outfit, gestures, event_categories, event_notifications, classified_categories, buddy-list, ui-config, login-flags, global-textures, END
2007-01-08T22:57:02Z INFO: LLUserAuth::authenticate: uri=https://login.agni.lindenlab.com/cgi-bin/login.cgi
2007-01-08T22:57:02Z WARNING: Packet from invalid circuit 66.150.244.151:12036
2007-01-08T22:57:02Z ALERT: LLXMLRPCTransaction CURL error 6: Couldn't resolve host 'login.agni.lindenlab.com'
2007-01-08T22:57:02Z ALERT: LLXMLRPCTransaction request URI: https://login.agni.lindenlab.com/cgi-bin/login.cgi
2007-01-08T22:57:02Z INFO: Processed response: 6
2007-01-08T22:57:02Z WARNING: Alert: [ErrorMessage]
2007-01-08T22:57:02Z WARNING: Alert: Unable to connect to Second Life.
2007-01-08T22:57:02Z DNS could not resolve the host name.
Could someone confirm that
WARNING: Packet from invalid circuit 66.150.244.151:12036 message shows even if client is connecting succesfully to the server?
Well, I've found this thread after my post here. Unfortunately there is no way to delete
your own message even if there are no replies

Best regards
Artur
PS. I'll try to change thread title to sth more appropriate.