> Can you reproduce this using CVS HEAD? Because I cannot from zsh -f and
> 
> zsh% autoload -Uz compinit
> zsh% compinit
> zsh% bindkey '^o' menu-complete
> zsh% gre<tab><C-o>

The error occurs with menu-select, not menu-complete. I can reproduce it 
with the following .zshrc:

autoload -Uz compinit
compinit
zmodload -i zsh/complist
bindkey '^o' menu-select

Strangely enough I can NOT reproduce it with 
zsh -f
source .zshrc