Can't expand my content tree becourse mysql timesout

from umbracolog:

At /umbraco/webservices/TreeDataService.ashx?rnd=6398163ada154407b9dc925862924fbc&id=1139&treeType=content&contextMenu=true&isDialog=false&rnd2=95.3 (Referred by: http://wunderwear.dk/umbraco/umbraco.aspx): MySql.Data.MySqlClient.MySqlException (0x80004005): Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.

   at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)

   at MySql.Data.MySqlClient.MySqlHelper.ExecuteReader(MySqlConnection connection, MySqlTransaction transaction, String commandText, MySqlParameter[] commandParameters, Boolean ExternalConn)

   at MySql.Data.MySqlClient.MySqlHelper.ExecuteReader(String connectionString, String commandText, MySqlParameter[] commandParameters)

   at umbraco.DataLayer.SqlHelpers.MySql.MySqlHelper.ExecuteReader(String commandText, MySqlParameter[] parameters)

   at umbraco.DataLayer.SqlHelper`1.ExecuteReader(String commandText, IParameter[] parameters)

Can connection Timeout somehow be changed?