If you ever run the set command and get any of the function definitions listed at the bottom of this entry then check your .bashrc file for the following entry.
# enable programmable completion features (you don’t need to enable
# this, if it’s already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi
If it is not commented out then it is likely that name completion has been activated elsewhere. Comment it out and start a new shell to see if it helps.
_alias _lvresize
_apt_cache _lvs
_apt_get _lvscan
_aptitude _make
_args _man
_aspell _mkisofs
_aspell_dictionary _modules
_available_interfaces _mount
_bzip2 _mplayer
_cancel _mplayer_options_list
_cardctl _nslookup
_cd _ntpdate
_cdrecord _ooexp_
_chgrp _openssl
_chown _openssl_sections
_chsh _perl
_command _perldoc………etc