I can't remember if it was on TS or a thread here in the forums (if it was, I can't find it), but I do remember someone complaining about not being able to keep the artillery destroyed on Dragon Valley. They said they'd blow it up over and over again and it wouldn't stay down.. By the time they got the third, the first was repaired.
Anyways, I found a thread on the EA forums complaining about it:
http://forum.eagames.co.uk/viewtopic.php?t=6097 and a link in there to Planet Battlefield also complaining about it:
http://www.forumplanet.com/planetbat...19&tid=1740509
Seems to be yet another bug... So, to whoever it was, you aren't crazy. Well, maybe you are, but this isn't one of the reasons why