Well one monitor is 19" narrow and the other two are 22" wide but this does not appear to be the problem because each one monitor works fine on its own.And two monitors work fine in eyfinity.The problem appears only in three monitor in eyfinity. The adapter is an active one. Maybe some settings in catalyst need to be adjust??
So, are you saying that you are trying to set up a 3 display Eyefinity using Landscape--Portrait--Landscape?
If this is your setup, Eyefinity does NOT support this type of configuration. All must be of the same orientation. All must be Landscape OR Portrait.
For further information, check out the FAQ at Rage3D:
http://www.rage3d.com/board/showthread.php?t=33962643