Chart componet error in ASP.NET 3.5 SP1

Question

i have downloaded the sp1 from the official site for visual studios 2008. i am workin on asp.net and have added the chart control present in the SP1 to my project.when ever i load my  project i get an error regarding httphandler something about "child request" i cant understand what it is. its not usual. sometimes error occurs, why is it so?