I've been aware of Blogger's atrocious timeout/relog cycle for several months now, but in a rush yesterday morning I managed to get snared by it anyway. If you enter the dashboard and create or edit posts, after some period of time (two hours?) any attempt to save or publish will send you to a login screen requesting that you re-enter your name and password. Then it will send you back to the dashboard without saving/publishing what you have written! Trying to back out won't help you either--the stuff is simply lost. So before other users attempt to do the same after a particularly long session, ctrl+n to replicate or ctrl+c after highlighting your html text before rolling the dice on whether or not Blogger will send your afflatus into the netherworld.
After spending a couple hours messing around with some numbers for a post I'd been working on, I'd to leave for work and hit 'save' before doing either of the two suggested above. My ramblings were unrecoverable and in a fit of rage I damaged the card table chair that serves as the throne to my home workstation. Screeching in anger also caused voice strain for a day. Don't become a victim of Google's beta-syndrome like I did--copy and replicate the page before going to save or publish.