Thats interesting... I have to admit the numbers will never/rarely be 0 :P

Lying flat on the desk mine is : 18,18,1188
Standing with the power button facing up : 54, -972, -162

Thats the closest result to yours :P

You can calls read/cat the values from here in terminal -
/sys/class/i2c-adapter/i2c-3/3-001d/coord

Pop onto this page to take a look at the standard outputs (2 pics!)
http://wiki.forum.nokia.com/index.ph..._N900_using_Qt


The way that seems to work to reset it is to remove the battery for a few minutes, then boot up again - it normally has recalibrated (if the actual hardware part has not beenknocked that is)