I've enabled the Custom Site Collection Help feature in my Sharepoint 2010 install, and verified that it works by creating a Help Collection folder and uploading some html files as Help Topics.
The problem is that the search box at the top of the help windows doesn't work - it just gives me a message of "Search Service Not Found.". It looks like this only occurs when I have the custom site collection selected in the search scopes drop-down, as when I select one of the default Sharepoint search collections, such as "Sharepoint Server 2010", I can search and find results. I've reset the search index, done a full crawl and can search for and find help content from the main site search page (using the All Content scope), but still get the "Search Service not found" result.
Has anybody else come across this problem and found a way resolve it? Is there another service hidden away somewhere that I have to enable?