[web2py] Postgres error

[Loreia]

Hi,

I define two tables in my application as:

    db.define_table( "block_names"
                   , Field("block_name"                 ,default=None)
                    )

    db.define_table( "block_data"
                   , Field("block_names_id"             ,default=None)
                   , Field("product_number"             ,default=None)
                   , Field("product_revision"           ,default=None)
                   , Field("product_path"           ,default=None)
                   , Field("branch"                 ,default=None)
                   , Field("bat_file_path"          ,default=None)
                   , Field("toolbox"                    ,default=None)
                    )

I am trying to run following query:
    rows = db((db.block_names.id > 0)
                 &(db.block_names.id == 
db.block_data.block_names_id)).select(db.block_names.block_name, 
db.block_data.ALL)

And I get this error:
  File ".../sqr_enumerate_pairs.py", line 77, in EnumeratePairs
    &(db.block_names.id == 
db.block_data.block_names_id)).select(db.block_names.block_name, 
db.block_data.ALL)
  File "/.../web2py/gluon/dal.py", line 7578, in select
    return adapter.select(self.query,fields,attributes)
  File "/.../web2py/gluon/dal.py", line 1315, in select
    rows = response(sql)
  File "/.../web2py/gluon/dal.py", line 1305, in response
    self.execute(sql)
  File "/.../web2py/gluon/dal.py", line 1392, in execute
    return self.log_execute(*a, **b)
  File "/.../web2py/gluon/dal.py", line 1386, in log_execute
    ret = self.cursor.execute(*a, **b)
ProgrammingError: operator does not exist: integer = character varying at 
character 309
HINT:  No operator matches the given name and argument type(s). You might 
need to add explicit type casts.

I am using latest 1.99.7 Web2py, latest 9.1.2 Postgres, and latest 2.4.4 
psycopg2 driver.

Any help is welcomed :-)

BR
Loreia