>There is a setting in SQL Server 2005 Management Studio that may effect this:
>
>Tools - Options - Designers - Table and Database Designers - Override connection string time-out value for table designer updates:
>
>I had this same problems changing some column definitions in a large table, and needed to increase that value to 30.

My default was already to 30. So, I increased it several times and up to 500. This never worked.

Thanks