CB problem

hi,

im using ECC+ - Joomla 1.5 plugin with google captcha.

everything is fine exept one thing.

whenever i try to register and put a wrong captcha it redirects me to:
/Community.html?option=com_comprofiler&task=registers&essp_err=check_failed

and shows me a white page , i think it must show a failed notice or something not white page.
i've tried to use sh404 but it only works if non-sef or sef url begins with index.php