On the A320 series you have to go by the Loadsheet C.G. and stabtrim setting as it does not indicate your actual C.G. on the ECAM.
The A330/340 have provision to indicate the C.G. location on the ECAM. It is necessary because of the trimtank and the associated fuel transfer.
So if you get two different figures on the ECAM and the Loadsheet it depends on your companies SOP, whether you can use the ECAM figure or not.
In our company if the difference is more than 2 % and the data entry into the FMGC is confirmed as correct we go by the ECAM figure and set the stabtrim accordingly.
But do not follow this procedure unless you get clarification from your company.
Regards,