Hrvoje Niksic <hniksic(a)srce.hr> writes in xemacs-beta(a)xemacs.org:
> Let's take a one-question bug-or-feature quiz:
>     In isearch, when you type in a capital letter, isearch becomes
>     case-sensitive.  However, when you delete the letter, the search
>     *remains* case-sensitive.  In fact, there is no way to make it
>     case-insensitive without exiting and reentering the search.
>     Bug or feature?
I vote bug.