Combat issues

I have been having several issues with combat ending early or not concluding. These include:
1: Ground Combat -- I have my troops landed, destroy the militia and all the buildings, so there is nothing else visible to be destroyed. However, the enemy planet's cargo shows that they have 5 mines. This continues in a never-ending cycle, because no matter how many buildings I destroy, the mines are never visible for me to destroy.

2: Space Combat -- Sometimes, combat concludes 5 seconds into battle. My ships have movement points, and there are enemy units in the system, yet the combat abruptly ends after only 5 seconds.

3: Space Combat -- I have ships travelling through a galaxy, taking warp points along the way. However, when coming through a warp point (this has sometimes happened in open space), with enemy systems in that sector, my ships appear outside the little circle of combat, and combat ends after 5 seconds. This continues until the movement points of the ships are depleted, and is VERY annoying.

Please help.

Thank you.