Kenneth Bull to SDL I noticed in trunk/SDL/src/video/win32/SDL_win32events.c, in this code here... ... if the device handle isn't found in mice[], which it won't be if the mouse was plugged in after SDL_Init, then you end up with an uninitialized value in index, which is then passed to various SDL_SendMouse* functions.

#!/bin/sh
#
# Print the current source revision, if available

srcdir=`dirname $0`/..

if [ -d $srcdir/.svn ]; then
    cd $srcdir
    (svnversion -c 2>/dev/null || svnversion .) | \
        sed -e 's,\([0-9]*\)[A-Z]*,\1,' \
            -e 's,[0-9]*:\([0-9]*\)[A-Z]*,\1,'
fi