First of all I'd like to say this mod is great, I've been enjoying it muchly.
One bug I've found so far is that on the hill between Chelm and Talchin (I was going from Chelm to Talchin), on the Talchin side of the slope, there's a point along there that I just cannot get past. When I click on my destination (if beyond this mysterious line) then my party just goes in the opposite direction, presumably to go round.
EDIT: Also when I tried to join in on a siege of an enemy town that a friendly invasion force was trying to take, the game crashed.