Disallowed Key Characters that don't seem to be able to fix in config

[eluser]shwonkbc[/eluser]
Okay, so I've tried adding a ? to $config['permitted_uri_chars'], and I tried directly copy pasting the comma in, and neither is working.

I've simplified it to 'www.MY-SITE.com?,' will throw the Disallowed Key Characters error. Thanks for those who've tried. Anyone else have any ideas? Is there a special way to include a comma?

Note:
$config['permitted_uri_chars'] is currently 'a-z 0-9~%.:_,?\-=';