The "official" rideshare board has had a good many technical problems over the last few years. There is, however, an "unofficial" backup : try this
. Registration is required.
If you have any questions, I'll be glad to answer them over on the Travel to Burning Man board
. Having spent more time dealing with the trollage on this board than I'd care to, however, I'm probably going to treat this post as a drop and walk, so don't expect a response here.