Randomly Freezing - Then Lagging Out

I and other players on my server, in certain spots, randomly freeze, then lag out.

No errors, but these are the plugins I am using. I'm pretty sure this is a client side bug.

Plugins (34): LagMeter, Minequery, WorldEdit, AutoSave, CommandBook, PermissionsBukkit, VanishNoPacket, Buycraft, WorldModes, Backup, pTerrain, bReport, ChannelChat, Vault, Multiverse-Core, WorldGuard, Jail, mChatSuite, InfinitePlots, BorderGuard, CraftBookCommon, Permissions, ZavAutoMessager, AcceptRules, NoCheat, InfiniteClaims, SimpleReserve, CraftBookCircuits, FoundDiamonds, CraftBookMechanisms, Multiverse-Portals, Multiverse-Inventories, HawkEye, BaseBukkitPlugin