I know this post is very old but I see this all the time and it frustrates me. People ask for help and the final post is a support person saying "create a support ticket". Then the rest of us have the issue, find the thread and the answer is no where to be found because no one ever came back and posted the answer. So I'm going to fix that for this thread.
Instead of creating a temp table in a SQL stored procedure like this:
CREATE TABLE #tmpTableName(
Use a SQL table variable in your stored procedure like this:
DECLARE @tmpTableName TABLE(Column1 int,Column2 int)
You can do the same things with a table variable as you can with a temp table and now your SQLDataSource and RadGrid will work too.