On Windows, pressing Shift+Backspace while in an editor
window will act just like a regular Backspace will,
however under Linux (Gentoo 2006.0 and
Slackware-current), instead of deleting the caracter
before the cursor, it inserts "^B".

Correct me if I'm wrong, but I don't think it'd be too
hard to fix this little annoyance.

(I would do it myself, but I'm not at all familiar with
IDLE's source layout)