This happened to me four times in the last 3 days or so.
I'd write something up, click save draft, then instead of the "warning page" where I need to click yes or no, it'd go straight onto load the "draft saved" page. And then my long replies to threads would just vanish into thin air.
Seemed to happen only to replies to others' threads, though. The drafts of new topics that I start are getting the "normal" warning page before the draft saved page and I can find them again (just checked with this post).
What is happening? Is this a warning that I shouldn't spend time at work browsing & replying to threads in the forum?