Merge replication sync fails after ALTER TABLE... NOT NULL

We have a SQL Server 2005 database that uses merge replication to sync to SQL Compact Edition subscriptions. We added a column to a table using:

ALTER TABLE Shifts ADD COLUMN StateOrProvince NOT NULL DEFAULT '  '

The SQL CE subscriptions will not sync, giving this error:

Alter table only allows columns to be added which can contain null values.

We figured out that the MSDN docs are in error, and that we should have used sp_repladdcolumn. But now we are trying to fix the sync problem. We have reinitialized all subscriptions and generated a new snapshot, but we still get the same sync error.

What are we missing?