wp_insert_post stopped working

Hello,
I got a website that users can post stuff with a custom made page i’ve constructed.

$post_title = $thetitle;
$post_status = ‘publish’;
$comment_status = ‘open’;
$post_category = $_POST[‘post_category’];
$postdata = compact(
‘post_type’,
‘post_author’,
‘post_content’,
‘post_title’,
‘post_status’,
‘comment_status’,’post_category’
);

global $wp_filter;
unset($wp_filter[‘wp_insert_post’]);

$post_id = wp_insert_post($postdata);

Everything worked fine until i reached post 1756, since then all posts that i try to post get an ID of 0, and you cannot repost after because of ID duplicate error. Can you tell me whats the issue? i’ve tried repairing the table but it seems fine.