rebels can 'take' your towers? wtf?

[Ambrosius]

the desert lands around tunisia and tripoli are HUGE. so i figure i want plenty of advanced warning so ill know if the egyptians are coming to attack my outlying cities, so i take a crapppy general unit and walk him ALL the way across to the ends of my lands, and place watchtowers there.

i just noticed my watchtower is 'gone'. wtf?
so i walk the poor bugger all the way back, and there is a small rebel army of 3 units standing next to my tower. so i figure ok, perhaps if you stand next to a watchtower you take control of it while you are adjacent? so i kill them.
3 turns later the watchtower is STILL a rebel watchtower. so strange...

is this a bug, or has this happened to anyone else yet?

[RexMortali]

Was it just on the border? Cause in my Hungarian campaing i built a town and in the next turn it went rebel too. Also couldnt take it back. Maybe its a border bug.

[Molina]

Probably a bug. I am always able to retake them. Try placing an army on the tower tile (assuming you haven't done it), that might work.

Rebels could take control of your towers in RTW, too.