getopts strange behaviour (Fedora)

[cs]

Configuration Information [Automatically generated, do not change]:
Machine: i386
OS: linux-gnu
Compiler: i386-redhat-linux-gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i386' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i386-redhat-linux-gnu' 
-DCONF_VENDOR='redhat' -DSHELL -DHAVE_CONFIG_H  -I.  -I. -I./include -I./lib 
-D_FILE_OFFSET_BITS=64 -O2 -g -pipe -march=i386 -mcpu=i686
uname output: Linux FC1-zalmoxe 2.4.30 #1 SMP Tue May 3 15:29:16 EEST 2005 i686 
i686 i386 GNU/Linux
Machine Type: i386-redhat-linux-gnu

Bash Version: 2.05b
Patch Level: 0
Release Status: release

Description:

    getopts builtin command problem when parameters lack

Repeat-By:

    While trying to use getopts builtin bash command I encountered the 
following problem:

    Test script:

    #!/bin/sh (/bin/bash)
    getopts ":xy" X
    echo $X
   
    The output for this script , ran without parameters is :

    Fedora Core 1

        [root@fc1 root]# sh script
        a
        [root@fc1 root]# sh script -t
        a
        [root@fc1 root]# sh script -x
        x
        [root@fc1 root]#

    Fedora Core 2
        
        [root@fc2 root]# sh script
        a f
        [root@fc1 root]# sh script -t
        a f
        [root@fc1 root]# sh script -x
        x
        [root@fc1 root]#
        
    According to the man page it should return `?' (question mark).

        Tests were also performed on Debian and Slackware distributions
        and the results were as expected. (OK)
        
    If there is something that I should've known, please let me know.
    
Chris.