turning off auto-save doesn't delete auto-save file

[Chris Moore]

In GNU Emacs 22.0.93.2 (i686-pc-linux-gnu, GTK+ Version 2.8.20)
 of 2007-01-23 on trpaslik
configured using `configure  '--with-gtk' '--prefix' '/usr/local' '--with-xpm' 
'--with-jpeg' '--with-png' '--with-gif''


I'm editing a large file on a slow USB flash drive.  Every so often,
Emacs auto-saves the file, which takes a long time, so I type:

  M-x auto-save-mode RET

to turn auto-save off for this file.

I finish work on the file and save my changes.

The #file# auto-save file is left on the disk, even after saving my
changes.

I would expect "M-x auto-save-mode RET" to have deleted the file when
it turned auto-saves off.  Either that, or saving the file should have
deleted the auto-save file.  One or the other.