We get the same thing and it's always from the same users, so I've always assumed it's on the users end not ours. If it were consistant and we got this error from every user I'd tend to believe it would be something that I could fix, but it doesn't seem to be so.
After this error comes up and the user is bumped off the server, they come back and we ask them what happened and they usually tell us stuff like 'i'm on a crappy college connection' or 'my mindcraft crashed again', stuff like that.
Private Mod Note
Rollback Post to RevisionRollBack
Minecraft Schematics at: MCSchematics.com
-A community creating Minecraft (MCedit) Schematics . Over 220,000 Members and thousands of schematics to download