Yes and it still happens now. I will mention, though, that when I use the search function in the FAQ's section, it works perfectly fine. But on the forums, it does not work. I went to Tickle Theater and the search function worked fine there for me. I noticed that when I also submit a reply or edit a message that I get the error message, but the post still is submitted or edited, the only problem with using the search function is that you can't press the back button and forward again or refresh the page, because it only brings me to an un-filled advanced search page.
I also want to add that when I submitted this, the error message didn't come up this time... let me try the search again...