This was observed on Mac OS X 10.5, running
Terminal.app. On a native Linux machine, from a
bash command prompt, typing meta-backspace deletes up until the most recent whitespace. On a Mac, it sounds the system bell.
SSHing into a Linux machine with
Terminal.app as the terminal causes the same problem.
This behavior is consistent with the third party application
iTerm. However, the Windows program PuTTy handles meta-backspace (and other meta commands) as expected.