Do you use SqlCommand.Parameters.Add("@Name","Value"); ?
Well, you're in for a shock, it's been depricated in ADO.NET 2.0.
When you move to 2.0, you should instead be using: -
SqlCommand.Parameters.AddWithValue("@Name","Value");
While the depricated code will still compile it will throw a compiler warning: -
System.Data.SqlClient.SqlParameterCollection.Add(string, object) is obsolete: Add(String parameterName, Object value) has been deprecated.
Use AddWithValue(String parameterName, Object value).
The depricated method will not work in .NET v-Next (2.0 +).
There are some other API changes in the framework, you can see a full list of obsolete and depricated methods for all versions of the framework on the GotDotNet .NET Framework Changes site.
Update: Reason for this change is posted here: http://weblogs.asp.net/JackieG/archive/2005/03/22/395517.aspx