| [1 <text/plain; UTF-8 (base64)>] | a recent checkin to cvs eliminated a very useful (ymmv) feature: M-r | and M-s behaved just like C-s when it was sequently pressed more then | once.
[I haven't updated in a while so I still get this behaviour -- with this behaviour, I dont know how to handle this scenario: Type a few characters, press M-r a few times getting a few matches, and _then_ modify the regexp being searched for, without having to start over]
an arrow key (in fact any other key then M-r), M-r again (history position is not reset), M-p for history in the minibuffer and modify the regexp. not as cool as C-s but good enough without a lot of extra code.