When you click "Z3950 search" in the intranet search results, the title field in the Z3950 search formis preloaded with the CCL for the query that you executed in Koha. However, when you try searching, you will always get no results back. If you take out the CCL, and just type in your query (like "heart") into the title field, you will get results.
I should really revisit this one at some point...
This one is kind of interesting... If you click "Z3950 search" in the staff client search results, and you've done any sort of search other than a basic keyword search, it's never going to work as it will include CCL prefixes. We probably shouldn't show the "Z3950 search" option when doing anything other than a basic keyword search, but that would involve additional detection... So this is a problem... but not a huge one.
It's really not that big of a deal, so I'm going to close this one