foregin table insert error

Hi,
I have a foreign table that I'm getting an insert error on:

horsedata=# insert into remote_cache (entry_id, name_id) values(2,1);
ERROR: null value in column "id" violates not-null constraint
DETAIL: Failing row contains (null, 1, 2, null).
CONTEXT: Remote SQL command: INSERT INTO public.cache(id, name_id,
entry_id, value) VALUES ($1, $2, $3, $4)

Here is the remote table client side:
horsedata=# \d remote_cache
Foreign table "public.remote_cache"
Column | Type | Modifiers | FDW Options
----------+---------+-----------+-------------
id | integer | |
name_id | integer | |
entry_id | integer | |
value | integer | |
Server: home
FDW Options: (table_name 'cache')

And here's cache server side:
horsedata=# \d cache;
Table "public.cache"
Column | Type | Modifiers
----------+------------------+----------------------------------------------------
id | integer | not null default
nextval('cache_id_seq'::regclass)
name_id | integer |
entry_id | integer |
value | double precision |
Indexes:
"cache_pkey" PRIMARY KEY, btree (id)
"cache_name_id_entry_id_key" UNIQUE CONSTRAINT, btree (name_id,
entry_id)
"ix_cache_entry_id" btree (entry_id)
"ix_cache_name_id" btree (name_id)

Any suggestions?

Thanks
Ed