This looks like when i try to boot mine while the battery is "empty", i.e. the charge is not enough to fully boot. For example happens after the N900 switched itself off caused by remaining charge depleted, and you try to switch it on right after this.

What gives 'cat /proc/bootreason' right after booting with the charger plugged in? I'm trying to remember, i read something in the level 3/4 service manual this week....