Sorry if I didn't made myself clear enough - I have observed the following multiple times:
Multiple "plopps" which traveled
through enemy dominion, and further on through no mans land, and settled 5 or 6 provinces away in an indie province (which had been indie since that start of game). My dominion remained there for several turns...
I wondered how this could be, and figured that somehow the dominion must have spread not to neigbouring province but neighbouring number - but that didn't seem right, as it wasn't exactly such a number. Now that I know about those traveling "plopps", I'm pretty shure that my assumption was/is correct.
Ah - just dug out 2 old savegames which clearly show that dom actually spread to a neigbouring province number in that case - from prov 8 to prov 7 ... which is
at least 3 hops away from any of my dominion. And it stayed there from before turn 37 on to turn 44 (and maybe longer..), despite high enemy dom in the neigbourhood!
To me the only possible explanation is that "plopps" leaked from my home province into that far away province... (yeah, I check the map file for errors, but all the neighbour declarations where ok).