Apostrophe and special characters in validfields?

[007]

What is wrong with this code I'm using?

$this->validfields['customfield'] = array(TYPE_STR, REQ_NO);

I am having issues with text that contains an apostrophe. This is being used in a few locations including threaddata_start and threadfpdata_start.

I've also put the following code under edit_post_update_start

$vbulletin->input->clean_gpc('p', 'customfield', TYPE_STR); 
$edit['customfield'] =& $vbulletin->GPC['customfield'];

Still, I get database errors when submitting text with apostrophes in this custom field.

Thoughts?