I have exactly the same problem -- and have had it since the change to this new board last year. After doing a search and going to the first thread, if I go "back," I get an error and lose my search and have to start the whole thing over again.

To avoid that, when I remember, I right click on the thread I want to read and then select "open in a new window," which allows me to view the thread, then close it without losing my search results.