asp.net2/c# - skinned controls using themes

Question

[img]http://foo.no-ip.org/images/skinerror.gif[/img] When I run the page, the skinned controls show correctly. But for some reason in design view the controls have errors on them. Is there a way to remove these errors? Are they false errors? If they are errors that I need correcting, how do I do so? The pages are working fine so this is confusing. Thanks in advance.