Has anyone else noticed websites who have dropped in SERPs and who also show no results for a link:www.xyz.com search? We have several sites that Google no longer sees any inbound links to even though the links still exist and show up in a similar link search on Yahoo.

The fact that Google sees no inbound links would explain the drop in SERP, but I don't have an explanation why Google suddenly stopped seeing inbound links.

I think more likely they just dropped showing links below a certain threshhold.

and yes it happened to me.