Technical issues and problems with WoGa.

Recently, a friend and I started playing Heroes of Might and Magic over Hamachi. Everything was fine, it worked. Until I attacked him in a castle. Out of three attempts to finish the battle (in different scenarios, sometimes I attacked him, sometimes he attacked me in the same castle), none were successful. It just shows that his unit is moving, and he sees that my unit is moving. And that's it.
Maybe there's a patch, or some settings? People play Heroes of Might and Magic online normally, as far as I know. Or should I install Armageddon's Blade?