Almost all homepages I maintain are built using docbook-website.
Unfortunately I'm not a big XSLT guru, so I'm having a hard time finding and fixing bugs in them. For that reason especially the netfilter.org homepage was suffering from problems with olinks.
Luckily, the 2.6.0 release of docbook-website seems to have fixed all the olink-related bugs I was experiencing. I just re-built the page and now all the cross-linking (including #localifo) is working fine now. Thanks to whoever fixed it :)