Really strange foreign key constraint problem blocking delete

Even if I try to delete the data entry in the table channel_mapping with
idaut 1622, it is not possible to delete from the table
tmp_autenticazionesocial with the error below. How is this even possible
since there is no channel_mapping with idaut 1622 any more?? I tried
this in Java under a transaction, but also in pgAdmin III.


ERROR:  update or delete on table "tmp_autenticazionesocial" violates
foreign key constraint "channel_mapping_idaut_fkey" on table
"channel_mapping"
DETAIL:  Key (idautenticazionesocial)=(1622) is still referenced from
table "channel_mapping".