What changed in 0.7.9 that made it so hard to "in Aslain's own words; crack the patch"

[TopAce6]

Firstly, no complaints here!
 I'm honestly just curious whats up, As i've played around with the mod tools for this game (nothing published just experimenting) , and made mods in other games years past.
from what i gather, war-gaming did some changes that haven't been done in a long time, i THINK! its something to do with texture rendering. but i wouldn't bet more then a dollar on that.