Thanks again for your post 
We checked the given steps of SAP Note "1153944" and all steps under ...
"2. Steps that have to be executed if one of the new datasources is going to be
used"
... are correct implemented (Change elements, created data elements, TCODE "FAGLBW03"):
Also table " FAGLFLEXT" contains data. We think if there is something wrong within settings also the update mode "FULL" should not work correctly.
Is there anything wrong or should we check something in the context of "RSA7" and "SMQ1"? It seems that there are no delta records available. Is there anything needed like a job control scheduling or something?