What is the full definition for dbo.tbl

I tried this

CREATE TABLE dbo.tbl (

ID int,

A bit NOT NULL DEFAULT (0),

B bit NOT NULL DEFAULT (0),

C bit NOT NULL DEFAULT (0)

);

INSERT INTO dbo.tbl

SELECT 1, 0,0,0 UNION ALL

SELECT 2, 1,0,1 UNION ALL

SELECT 3, 0,1,0

and it all worked fine - so perhaps you have other constraints on your version?