Mouse wheel doesn't work on XP

[RGB]

It's been about a week since I compiled Emacs.
Yesterday I did and the mouse wheel stopped working.
Moving it results in:

<wheel-up> is undefined
<wheel-down> is undefined
<double-wheel-up> is undefined
...

Oddly enough, the messages don't appear in the *Messages* buffer,
only in the echo area. 
I don't know if that's a separate problem or by design.


In GNU Emacs 22.0.50.1 (i386-msvc-nt5.1.2600)
of 2005-11-01 on LD1
X server distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-msvc (12.00)'

Important settings:
 value of $LC_ALL: nil
 value of $LC_COLLATE: nil
 value of $LC_CTYPE: nil
 value of $LC_MESSAGES: nil
 value of $LC_MONETARY: nil
 value of $LC_NUMERIC: nil
 value of $LC_TIME: nil
 value of $LANG: ENU
 locale-coding-system: cp1252
 default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
 encoded-kbd-mode: t
 tooltip-mode: t
 auto-compression-mode: t
 tool-bar-mode: t
 mouse-wheel-mode: t
 menu-bar-mode: t
 blink-cursor-mode: t
 unify-8859-on-encoding-mode: t
 utf-translate-cjk-mode: t
 line-number-mode: t

Recent input:
<down-mouse-1> <mouse-1> <help-echo> <help-echo> <menu-bar> 
<file> <open-file> <help-echo> <wheel-up> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<menu-bar> <help-menu> <report-emacs-bug>

Recent messages:
(C:\emacs\bin\emacs.exe -Q --no-splash)
Loading encoded-kb...done
For information about the GNU Project and its goals, type C-h C-p.
Loading emacsbug...done