How to disable the lost network connection warning on OSX
From this article: http://whatsamknows.tumblr.com/post/37368603810/get-rid-of-server-connections-interrupted

The following steps should sort you out:


Click on the spotlight icon (magnifying glass) in the upper right of your screen 
Type in ‘terminal’ 
Click the ‘Terminal’ icon (black with white border) under
applications
Type in the following command and hit enter:
sudo mv /System/Library/LoginPlugins/FSDisconnect.loginPlugin /System
It will prompt you for your user password. Type it and hit enter again
Reboot