It appears to me the Vasari is broken in a couple ways in regards to mining operations:

1) Setting up the ship to automatically lay mines fails to do that.  Rather, it just moves back and forth without dropping mines despite having plenty of resource

2) When the Navigator approaches an enemy mine, the mine activates and attacks the ship.  This is completely different behaviour for others where the scout ship approaches a mine and the mine lays dormant and able to be killed by the scout or strike craft.