[gommm]

Cool website... I run it on a project and it says: WWW Resolve

This website without www doesn't redirect to www (or the opposite). It is duplicate content.

but it actually does redirect with a 301 redirect.

One other question, where does it get the Visitors data it displays?

[splitbrain]

Have the same problem for mine (www.splitbrain.org). It complains about unclean URLs which look just fine to me.

[statsgram]

I use Alexa API.

[statsgram]

Please recheck your website.

[ivanhoe]

I've noticed the same: My site does 301 redirect www -> no-www, but you service doesn't detect this properly (I've entered the url without www). I've double-checked the headers on my site, the problem is in your script...

[gommm]

I did curl -I indicates a 301 redirect...