Hello Lasse,
The MP3V5004G is laser trimmed, but offset can shift due to temperature changes, mechanical stresses (mounting stresses) and aging. Since there tends to be an endless amount of various applications and conditions there has been no way Freescale can validate the application impact on product reliability or lifetime.
I would recommend you to take a look at AN1636 which describes how to implement an autozero function in order to correct the sensor output for longterm offset drift or variation.
http://cache.freescale.com/files/sensors/doc/app_note/AN1636.pdf
Hope it helps.
Josh
