If you are a regular player to the server, then we at KcV2 staff are sorry that these server downtimes are becoming a frequent problem after the recent upgrade.
Basically, our problem seems to lie within the server files (And SpaceBukkit, I may be wrong). The server seems to be randomly shutting itself off at an unexpected time (So far no pattern has been spotted) without the world being saved, this of course causes 1 pretty darn big issue, it rolls back the world by about 10 minutes before the server died.
So for now our solution is to keep the server down and shut off so that you don't loose any major progress you might make in your builds.
Again sorry for this inconvenience, and there is yet to be an estimated time as to when the server can be back on-line again.