Those of you who’ve used MSN via Adium on Leopard may have observed Adium taking a very long time to connect, or not connecting at all. A lot of you sent us bug reports about this.

The problem wasn’t a bug in Adium, or even in Libpurple. In Mac OS X 10.5.0, Apple changed the way it looks up hostnames, such as the one for the MSN server. They changed it to use a “SRV” request instead of an “A” request.

Unfortunately, some ISPs’ domain-name servers only knew how to handle “A” requests, and would ignore the “SRV” requests. That’s what was causing the problem: broken domain-name servers.

In Mac OS X 10.5.3, Apple changed its lookup method back to the earlier behavior. So, for those of you who had this problem, MSN should now connect again, without workarounds such as using OpenDNS.