CAPTCHA does not appear

Status: 
Open
Question: 

Register a new account. The CAPTCHA-picture is invisible(Firefox), hence registration impossible. In Safari you see the placeholder for an image). Is this a server, drupal or package issue?
http://geh-abnehmen.com/?q=user/register
I have checked the .ttf files in the
/sites/all/modules/captcha/image captcha/fonts. Seems ok.
Thanks for help in advance

Responses

1. does nobody know, why...

the Captcha image does not appear?.
http://www.geh-abnehmen.com/?q=user/register

First i have de/selected the module, then installed a new one. Nothing helped.

2. View

Its really a problem but if it continues then try the myCatcha module,

i think that works fine

3. changed to mollom

Thanks for the info, xtreme.
I m a drupalnewbie, hence i often not know whats the problem: the hoster, the drupal complexicity or just me.
I tried Mollom before and it worked. Are any disadvantages to myCachta?