Local data base, you lose the connection to the Internet falls (no replies)

I raise my problem:

I have MySQL installed on a Ubuntu Server, designing an application in VS2010, use the connector. NET MySql. That is all my work is local, the system was working fine until one day I had no Internet, and let you connect to the database.

Curious thing is that when I have internet application works well, and when no internet connection I lose mad.

What is my problem??

Sorry for my english .. :-(