Auto Save messes up version number

[EB@MIT-OZ]

I have Auto Save mode turned on.  Suppose I do the following:

    edit FOO.TXT with ^X^F; say the actual version is FOO.TXT.69
    make a change in FOO.TXT
    get out with ^Z^Z, thus forcing an auto save
    get back in
    do M-X Revert File

Then the version number for FOO.TXT in the mode line will not be 69 as
it should be, but will be FOO.TXT.1 (or whatever the version number of
the auto-save file was).

This confuses numerous parts of Emacs, so I generally have to kill the
buffer and read the file in again.