To break the Browse Results box added in Bug 6483: 1. search for many pages of results common, like "a"; 2. open results page 2 in a new tab; 3. open any result detail from page 1; 4. enjoy the Browse Results box either: moving you around the wrong page; or having previous/next greyed out while Back to Results takes you to the wrong page. This is because the Browse Results links are stored in the session rather than encoded in the URLs. I think it needs more behind-the-scenes knowledge than even OPAC power users will have before you expect that behaviour, but power users open results pages in tabs. The obvious fix is to encode the session parameter busc in the URLs rather than the session. That would also make it rather easier to debug things like bug 7394 and bug 7894.
*** This bug has been marked as a duplicate of bug 10829 ***