Whenever I apply Ctrl+y, nothing happens (it was supposed to apply filters and it used to work before).
It seems to be a problem for imap4 only. Same bug as http://bugzilla.gnome.org/show_bug.cgi?id=317439
please upgrade to evolution-2.6 ( just marked stable with GNOME 2.14 ) and re-open the bug if you can still reproduce it.