Case-insensitive completion isn't completely insensitive

[Kai Grossjohann <kai@xxxxxxxxxxxxxx>]

I have customized zsh (4.2.0) completion as shown below.  I like
case-insensitive completion.

I have a directory which contains a file ENV and a subdir etc/.  I
change into that directory, type "source ./e" and then hit TAB.  Zsh
completes the directory, but not the file!

Typing "source ./en" and then hitting tab completes ./ENV as I prefer.

Is there a way to get zsh to complete ./e into ./ENV in this
situation?

tia,
Kai

# The following lines were added by compinstall

zstyle ':completion:*' auto-description 'specify %d'
zstyle ':completion:*' completer _expand _complete _correct
zstyle ':completion:*' completions 1
zstyle ':completion:*' format 'Completing %d'
zstyle ':completion:*' glob 1
zstyle ':completion:*' list-colors ''
zstyle ':completion:*' list-prompt %SAt %p: Hit TAB for more, or the character to insert%s
zstyle ':completion:*' matcher-list '' 'm:{a-z}={A-Z}' 'r:|[._-/]=** r:|=**' 'l:|=* r:|=*'
zstyle ':completion:*' max-errors 3 numeric
zstyle ':completion:*' menu select=long
zstyle ':completion:*' select-prompt %SScrolling active: current selection at %p%s
zstyle ':completion:*' substitute 1
zstyle ':completion:*' verbose true
zstyle :compinstall filename '/home/kgr/.zshrc'

autoload -U compinit
compinit
# End of lines added by compinstall