This is a merged sytem running on a network drive with Mark of the Web enabled for each of the projects in the Subsystems folder. The links to the search results topics in these subsystems look like this:
file:///[drive]:/[path]/Index.htm#../Subsystems/[path]/[topic].htm
If you remove the ../ after Index.htm#, then the link works.
I'm in the process of submitting it as a bug, but I thought I'd see if anyone else had seen this.
Thanks