HELP: item is null

[eluser]cestaz18[/eluser]
my firebug show this error....

Array
(
[company_code] => aaaa
[company_name] => aaaa
[id] => _empty
[oper] => add
)
{"item":null}<br />
<b>Fatal error</b>: ob_start() [&lt;a href='ref.outcontrol'&gt;ref.outcontrol&lt;/a&gt;]: Cannot use output buffering in output buffering display handlers in <b>C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\comunion\system\libraries\Exceptions.php</b> on line <b>162</b><br />