It's a weird bug that happens for some people but not for others. I've seen i a couple of times but I've not been able to reproduce it. I haven't seen the error before though. Is it a valid error or does it seem random?
Could this be a replication problem with the way you host ez.no? One server has the db with the new draft but when you publish its not on the other box you replicate to?
As far I can remember I had that problem at my linux installation too. It was a memory problem. I increased the php memory limit and the error was away.
(If no "error page" is shown its a memory problem mostly.)