Python shell interpreting delete key as tilde?

[Leif K-Brooks]

I'm running Python 2.3.5 and 2.4.1 under Debian Sarge. Instead of
deleting the character after the cursor, pressing my "delete" key in an
interactive Python window causes a system beep and inserts a tilde
character. This behavior occurs across all of the terminals I've tried
(xterm, Konsole, real Linux terminal), but does not occur when running
bash instead of python. Other Readline-provided functionality (moving
the cursor, history) seems to work fine.

The delete key was working fine in Python up until a few days ago, and I
don't remember making any changes that should have affected it.

If anyone knows what could be causing this problem, please explain. It's
driving me crazy!