The only suspect i have now, is that it could need a captcha plugin, but i read some code, and don`t looks like (and if needs, which one captcha plugin? anyone?)

looking into my com_comment/error_log i found that :

[11-Jul-2009 14:02:13] PHP Warning:  imagecreatefrompng(captcha/bg1.png): failed to open stream: No such file or directory in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 29

[11-Jul-2009 14:02:13] PHP Warning:  imagecolorallocate(): supplied argument is not a valid Image resource in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 47

[11-Jul-2009 14:02:13] PHP Warning:  imagecolorallocate(): supplied argument is not a valid Image resource in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 48

[11-Jul-2009 14:02:13] PHP Warning:  imagettfbbox(): Could not find/open font in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 50

[11-Jul-2009 14:02:13] PHP Warning:  imagesx(): supplied argument is not a valid Image resource in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 54

[11-Jul-2009 14:02:13] PHP Warning:  imagesy(): supplied argument is not a valid Image resource in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 55

[11-Jul-2009 14:02:13] PHP Warning:  imagettftext() expects parameter 1 to be resource, boolean given in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 57

[11-Jul-2009 14:02:13] PHP Warning:  imagettftext() expects parameter 1 to be resource, boolean given in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 58

[11-Jul-2009 14:02:13] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/samir/public_html/components/com_comment/joscomment/captcha.php:29) in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 60

[11-Jul-2009 14:02:13] PHP Warning:  imagepng(): supplied argument is not a valid Image resource in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 61

[11-Jul-2009 14:02:13] PHP Warning:  imagedestroy(): supplied argument is not a valid Image resource in /home/samir/public_html/components/com_comment/joscomment/captcha.php on line 62

Any clue?

Thanks!