Type ‘System.Web.UI.WebControls.Parameter’ does not have a public property named ‘DbType’#

In Visual C# 2005 SP1, I added an object data source to a web page that uses my business class as the select method. The method has one parameter of type Guid. The data source wizard generates code like this

<asp:Parameter DbType=”Guid” Name=”rowId” />

Although the web server has .Net 2.0 SP1 installed (I checked the registry), it still throws an error

Type ‘System.Web.UI.WebControls.Parameter’ does not have a public property named ‘DbType’

The walk around is easy:

<asp:Parameter Type=”Object” Name=”rowId” />