hey Tom,

So this is weird. I went ahead and looked at the page in question and I see what you're talking about. I would question OSE's crawl of your site and direct that toward the moz-staff. Here's the reason:

The Just Discovered tool is showing a buttload of links coming to your page.. like 8 pages worth or something crazy. The inbound links section shows 2 domains... not sure what's up there.

If it were my site I'd spend more time and cross reference that with GWMT and maybe grab Majestic and AHREFS reports as well. Also, take an OSE inbound link list of the subdomain and see if the just-discovered links from the page in question show up there.

While I agree you should address that issue, I don't think it would have much to do with the OSE indexing. I would definitely attempt to contact a moz staffer, I think your case warrants one. Surprised they haven't stepped in with an answer yet they're usually on top of these forums.

props to Matt! He nailed it.

If the server isn't actually returning a 404 response then those links are still actively pointing at your domain. Just because you point them at a custom 404 page doesn't mean it returns a 404. In fact, in your case it's clearly returning a 301 which passes link juice.

A 302 does not pass link juice and might be the better option, but I'm not sure that even will be your best bet. Your best bet is to delete the pages in their entirety and re-create them with different URLs.

Well, your best bet is to remove the poison links but trust me I know how impossible that can be.

Anyway.. Hope this helps.