Whenever I join a network where there are other Macs, I sometimes get the notification:

> 
> This computer's local hostname
>  Macintosh.local is already in use on
>  this network. The name has been
>  changed to 'Macintosh-2.local`.
> 
> 
> 

From then on the result of `hostname` is this changed name. I've tried:

* System Preferences->Sharing->Computer Name.
* `sudo hostname jared-mac`.
* Modified `/etc/hostname`.
* System Preferences->Network->Advanced... ->TCP/IP DHCP Client ID
* System Preferences->Network->Advanced... ->WINS

Is this a known issue? Or am I doing something wrong?