Whats Up with the server lately?

It constantly kicks me and a lot of other people off, we were "flying" according to the server (if by that it means standing in place while placing a block). Other than that, its also been really laggy. Normally I would not post about this but this has been continuing for a while. At this point, I cant even log on anymore. Any idea whats going on?

It's due to the lag, Bukkit is trying to read the packets and is failing to interpret them correctly. We've been having bad lag since we updated Craftbukkit, so it's probably one of our plugins causing some trouble.

It is also people buying really fast or people are in the nether. Although, I think the nether is shut down for now.