Or before restart, try lsmod | grep lis302 lsmod lists the loaded kernel modules (=drivers).
What you might try is restart the N900 and then run the command dmesg | grep lis302 from x-teminal (you might need to be root) This might show startup messages to do with that driver.
Alternatively dmesg | more and visually inspect to see if you can see any messages related to the lis302dl driver (that's the name of the accelerometer chip I think)