[Mediawiki-l] thumb pages with error messages (only with Netscape 7.1)

[Markus Klaus Schäffauer]

Hello,

MediaWiki 1.3.3 is giving strange error-messages on pages with thumbs, 
but only when I use the browser Netscape 7.1 and not with IE 6.0 or 
Firefox 0.9.
The error messages are the following:

    Warning: shell_exec,popen,escapeshellcmd,proc_open,proc_nice() has
    been disabled for security reasons in
    /www/htdocs/wiki/includes/Image.php on line 179

    Warning: stat() [function.stat <http://www.php.net/function.stat>]:
    Stat failed for
    /www/htdocs/v101777/wiki/images/thumb/5/57/180px-Kvdr-image02.jpg
    (errno=2 - No such file or directory) in
    /www/htdocs/wiki/includes/Image.php on line 246

    Warning:
    unlink(/www/htdocs/v101777/wiki/images/thumb/5/57/180px-Kvdr-image02.jpg)
    [function.unlink <http://www.php.net/function.unlink>]: No such file
    or directory in /www/htdocs//wiki/includes/Image.php on line 249


Has anybody a idea what is going wrong? What can I do?

Thank you!
Markus