Randomly moving when attacking monsters

[Oren]

Why when attacking a monster standing next to me I will sometimes automatically go around it and attack it from another position? I'm standing next to it to begin with, after all, so why should I move at all? It's hard to plan strategy this way, when I just seem to move to a random place when attacking monsters.

[Paksenarrion]

It happens to me only when I try to directly attack.
Now, I move the unit first and then attack - all in the same turn.

[phoenixreborn]

It is entirely dependent on where YOU place the cursor. Move it all around to see the different sword angles. The only case where something funny might happen is if a unit is not under your control due to fear or leadership issues.