There is a problem with this validator that happens quite regularly with the "Check by URI" option. That is: you submit a URI, it validates perfectly, but when you try to validate it again, it produces this error:
"An attempt to load the RDF from URI 'http://www.beta.jdclark.org/meta.rdf' failed. (Undecodable data when reading URI at byte 0 using encoding 'UTF-8'. Please check encoding and encoding declaration of your document.)"
This happens even if you re- submit the *exact* same RDF file without any changes, so you *know* it is perfectly valid.
Otherwise, this is a very useful tool. The "Check by Direct Input" works perfectly every time. Thanks for your efforts in providing it, and thanks in advance for your time in looking into this.