Only works on first postback

Feb 2, 2010 at 12:38 AM

I have a dropdownlist with around 3500 items in a user control and then placed on aspx page inside an updatepanel.  I have the sideriteajax.dll and browser file in my project.  On first postback it works fine but on subsequent postbacks it's slow.   Any body else experience this?  Is there something else that needs to be configured/done?  Thanks!