Having suffered a few similar incidents I always type long posts in notepad or MS Word (saving frequently) and then copy and paste the finished reply.I'd just composed a long detailed reply to a PM, clicked Send, and the server change started at that instant!
And yes, you've guessed, when the site came back online, my reply was nowhere to be seen.
So my long suffering keyboard has just come in for a duplicate bashing, not to mention my brain wracking to remember what I'd typed this morning.
Sob.
.