Permission denied for sequece...

Hey,

I'm in the process of porting an app from MySQL to PostgreSQL and am
pretty new with PostgreSQL and am having permission problems.

First, a little background info.
- The postmaster is set to startup with -i and i'm able to actually
connect without an exception.
- I've added the following lines to the pg_hba.conf files (for testing purposes)
local all all trust
host all all 127.0.0.1 255.255.255.255 trust

I create my db, as follows:
createdb testdb

then i log into psql and run the following
CREATE USER testuser PASSWORD 'default';
GRANT ALL ON DATABASE testdb TO testuser;
GRANT ALL ON [my table names] TO testuser;

In my app i connect to the db with the following, which is run without issue.
connection = DriverManager.getConnection("jdbc:postgresql:testdb",
"testuser", "default");

I then call the following insert
INSERT INTO Property (Name,Value) VALUES ("some name", "some value")

and get the following error

org.postgresql.util.PSQLException: ERROR: permission denied for
sequence property_propertyid_seq

The sql used to create the property table is

CREATE TABLE Property
(PropertyID SERIAL PRIMARY KEY,
Name VARCHAR(64) UNIQUE NOT NULL,
Value VARCHAR(255) NOT NULL);

Can someone tell me what would cause this error message to occur and
suggest ways that i could fix it?

Thanks,

Jon Horsman