Postgres fixtures and sequence id field


I’ve a problem testing my application.
Basicly when tests try to load the fixture in my postgresql database I
obtain the error

currval of sequence “my sequence name” is not yet defined in this

The problem is the ID field: basicly the fixtures try to add
explicitly a defined ID but postgres don’t like this, even if I build
a brand new DB and try to push the id 1.

How can I make the fixtures load smoothly in the test DB?

My sequence name use a non standard rails name since my DB is coming
from a legacy system.