Update SqlDataSource with ODBC.NET

Hi,
I have an SqlDataSource on my ASP.NET page, UpdateCommand of which is
set to "Update table set @f1=f1, @f2=f2 where @id=id". When bind to a
grid and properly populated, it automatically gets to edit mode and
updates data when using SqlClient as provider. However, when provider
is changed to Odbc, I get error: "Must declare scalar variable @f1"
I guess this is an ODBC specific problem, because NOTHING else is
changed. What is the problem with it?