All this while I hadn't checked out what the maemo wiki said on this topic, and the first thing they say is to disable RD mode. I had done that a long time ago to look at the bootup messages and forgot to turn it off since then. I've disabled it now, and the tablet's been running in a semi idle state for three hours with just .01 percent drained. Wow!
BTW, this text was written in maemo-wordpy. Check it out in case you haven't heard about it, it's cool stuff.