Problem with 07.03.0100 in ASP.NET page

I just recently upgraded from 7.2.5 to 7.3.0100. The web page that I
written in ASP.NET work fine under 7.2.5 but now that I've upgraded, I get
the following message.

Failed to enable constraints. One or more rows contain values violating
non-null, unique, or foreign-key constraints

My table is defined as:

CREATE TABLE pcidxref (
pcid text NOT NULL,
store text NOT NULL,
email text,
CONSTRAINT pcidxref_pkey PRIMARY KEY (pcid)
) WITH OIDS

My select statement is just SELECT pcid, store, email from pcidxref. From
the sounds of the error, I've either got null data or non unique values but
I don't. There's no duplicate key and all fields have data in them. I've
also got no foreign keys. Any suggestions?

Patrick Bye
Programmer / Analyst
Westfair Foods Ltd.
pbye(at)westfair(dot)ca
(403) 291-6538