This is what I get after using json_decode() and var_dump on the cURL's response:
array(1) { ["errors"]=> array(1) { ["customer"]=> string(26) "Required parameter missing" } }
Is this what you're refering to? I'm new to Shopify, and I just based my code on what is writtern here: http://docs.shopify.com/api/customer#update and then perform a cURL request for it.
Thank you.