Eek! I haven't had that one happen. The forum is run on a commercial hosting facility in the midwest US. And it has a features that, if you checked "remember me" when you logged in, it will keep you logged in "forever". I run the PingDom monitoring system on the forum that checks from 20 places around the world (to eliminate connectivity problems from the test). It's showing 100% up time over the last week (see below). Finally if you "lost it" while creating s message or reply, then go back and reply again later, and if you are using the same browser (it uses cookies) you will usually see a "restore previous" button at the bottom, and clicking that will restore all up to its last "autosave" (which is every minute or two)

1. Click here to go to the message to which you were replying
2. Look for the Restore post button in the bottom of the reply field and if there click it

That's as much as I can give you right now. My apologies... it's a commercial forum system so I don't know much about it internally.