i disabled all the failures but it doesn't seem to work . and then i tried to switch to another DEU still not working anyone has any idea what this is all about? thanks

You need to make sure the FO altimeter reads the same altitude as the Captain altimeter. Make sure they are both set to the same barometric pressure. Page 10.2 of the QRH.

but i did i made sure the settings were the same but in fact it doesn;t help before takeoff they are exactly the same, but shortly after lift-off the messenge appears and the two altimeter start to differ

Try this: http://forum.avsim.net/topic/342468-alt-disagree-problem/page__p__2048637#entry2048637

whaoo it works thanks man!~

whaoo it works thanks man!~

No probs, credit goes to the person who posted the fix. But it is still rather annoying that you can't use metric... My opinion anyway.