trouble with primary key element in a dataset

Hi,

I've got a dataset containing two elements in a table
called tblCollection: Collection_ID and CollectionName.
Collection_ID is an int (not an autonumber).

In my stored procedure that inserts a new record, I create
a new unique id. I use 4 stored procedures to get and save
the data because I want to perform some tests.

So I bind the dataset to a datagrid (I only show the
Collection column), but I can't insert any new row because
of the null value of the Collection_ID, even when I set
the nullability true in the dataset properties of that
Collection_ID element.

When I use default value 0, I can only create one new
record because (offcourse) the Collection_ID must be unique

Has anybody a solution?

Thanks a lot,

Filip