Hi guys,
Think we've found the problem.
1. Do not put any port number in Internal Address in mySQL service settings. MS Deploy uses this address but do not accept port numbers. For example: you should specify 'localhost' instead of 'localhost,3306'
2. If your MS Deploy and mySQL are located on different servers, please note that for internal address you cannot use 'localhost' anymore. You should specify IP, that used by you to connect to your mySQL from another server. Simply saying - your external IP. In this case external and internal addresses are the same in mySQL servie settings.