Can't submit to Digg. What's wrong?

Anyone experience any troubles submitting content to Digg? I am unable to submit nothing from domain www.wmtips.com. For example, URL of the article "How much are Google, Yahoo and MSN able to index?" is valid, but I keep getting “This link does not appear to be a working link. Please check the URL and try again.â€x9d Site is built on custom CMS and do not use any security add-ons like Bad...

Can't submit to Digg. What's wrong? WordPress ...