ido-mode breaks filename completion in recursive minibuffers

[Chris Moore]

run Emacs:
  $ emacs -Q

enable recursive minibuffers:
  M-x set-variable RET enable-recursive-minibuffers RET t RET

enable ido-mode for switching buffers:
  M-: (ido-mode 'buffers) RET

start switching buffers, but don't finish:
  C-x b

switch away from the minibuffer:
  C-x o

try finding a file, notice that TAB lists buffers, not files
  C-x C-f TAB

(TAB (translated from <tab>) runs the command ido-complete, but I'm not using 
ido-mode to complete filenames).

In GNU Emacs 22.0.96.9 (i686-pc-linux-gnu, GTK+ Version 2.8.20)
 of 2007-03-24 on trpaslik
Windowing system distributor `The X.Org Foundation', version 11.0.70101000
configured using `configure  '--with-gtk' '--prefix' '/usr/local' '--with-xpm' 
'--with-jpeg' '--with-png' '--with-gif''