Fatal error: ob_start()

[eluser]ilSignorCarlo[/eluser]
Hi,
all of a sudden on the homepage of the site I developed some time ago it appeared this error:


Fatal error: ob_start() [<a href='ref.outcontrol'>ref.outcontrol</a>]: Cannot use output buffering in output buffering display handlers in ..../system/libraries/Exceptions.php on line 160

I searched around and read about compression and a setting relative to this in the config.php file, $config['compress_output'], but in my config it is already set to FALSE.

What else can I check/do?

Thanks.