Search function time-out

So if I spend more than 10-15 minutes looking at a thread found through the search function, and hit the back button to get back to the list of threads that the search found, I get a "Sorry, your search turned up zero matches" message.

Then I have to go back to the main page, and redo the search.

What's up with that? Is there any way to save the search list so it is still clickable?