1) Just before I achieved victory I noticed new Rebel generals were entering the map via Canada- then travelling east to the Hudson River and going to their lines by the river movement system, or travelling directly south down to their lines- at a rapid rate of knots I might add.
2) Some strange movement paths from and between the Western off-map boxes: here are a couple of examples (all are for infantry);
a) A 30 day travel-time between the South West and the Great Plains.
b) A 33 day travel-time between the South West and the Northern box of The Rockies, whilst a journey to the box below The Rockies (Oregon) takes 116 days.
c) A 16 day travel-time between the South West and the northern province of Decatur, KS (located directly below Sioux City).
d) I have noticed many other odd movement paths from these boxes that the AI was able to exploit by suddenly appearing in my NW territories in force once she had taken the South West box, forcing me eventually to gather a LARGE

e) Finally one odd path bug that didn't end up translating into time-warp travel: I went to move a militia unit from Kittang, PA to Johnson City (Carter County, TN) and was given this path: Kittang-->Jefferson County (adjacent, 5 days)---> Jefferson County (direct)---> Johnson City (6 days).
Hope this helps!