Enabling aggregate and compress CSS files caused error on site access I set this tick box in the performance area, and on clicking Save I now cannot access the site, even the performance area to disable this! any one know if I can directly change this in the DatabasE?

EDIT: 
I have refreshed the Database, thankfully no updates since it went live. This does raise the question though as I'm not the only one who has had problems with these performance tick boxes, how do you back out of an error?

I would still like the answer cause i'm trying to get to the bottom of these performance settings.

thanks for any replies.
I found this from http://drupal.org/node/782510

In your settings.php file, add

$conf['preprocess_css'] = CACHE_DISABLED;


Seemed to work for me on a quick test