I was trying out the Windows version and in the Preferences:Logins screen, there is a help link at the bottom of "can I use a single login item for multiple web sites". This link goes to the Domain Matching in Internet Explorer help page on your website. However the image on the page is not loading. I tried loading it directly at http://help.agilebits.com/images/1Pwin_DomainMatching.png and only get a 404 error page.
Hope this helps.
P.S. Please tell me you are adding this Domain Matching feature to 1PW4 on the Mac.