wp_insert_post not working when placing after wp_upload_bits

hi!

i have a short plugin that downloads images and some information in one of my websites and creates a post out of the images and information taken, i’ve used the following codes to do it:

$newfile = “someurl”;
$file = wp_remote_fopen(url);
wp_upload_bits($newfile, null, $file);

if i place

$postarr = array(
‘user_id’ => $user_ID,
.
.
‘fieldn’ => valueN
);

$id = wp_insert_post($postarr);

before the code with wp_upload_bits(), the post is created

but if i place it after the wp_upload_bits() code,

the wp_insert_post() fails

what seems to be the problem? Thanks in advanced.!