postgresql converts the 'serial' datatype internal into a sequence using the name scheme <tablename>_<fieldname>_seq, which is not followed by umbrello exporting an entity attribute with auto increment enabled.

Reproducible: Always

Steps to Reproduce:
1. start umbrello
2. create an entity 'limited_areas_towns'
2. Add an attribute 'lat_id' and set autoincrement
3. select postgresql as active language
4. export the entity


Actual Results:  
The following statements are created 
CREATE SEQUENCE limited_areas_towns_lat_id START 1 INCREMENT 1 ;
ALTER TABLE limited_areas_towns ALTER COLUMN lat_id SET NOT NULL;
ALTER TABLE limited_areas_towns ALTER COLUMN lat_id SET DEFAULT nextval('limited_areas_towns_lat_id');


Expected Results:  
The following statements should be created (note the appended '_seq')

CREATE SEQUENCE limited_areas_towns_lat_id_seq START 1 INCREMENT 1 ;
ALTER TABLE limited_areas_towns ALTER COLUMN lat_id SET NOT NULL;
ALTER TABLE limited_areas_towns ALTER COLUMN lat_id SET DEFAULT nextval('limited_areas_towns_lat_id_seq');