I was using cURL in PHP to POST some data to a URL earlier tonight and ran into this problem.
With VERBOSE on cURL was erroring with the following error:
"Received problem 2 in the chunky parser"
After some Googling it turns out this is a problem with how some servers respond with chunked encoding.
A simple fix for this is to set the HTTP version cURL is using to 1.0:
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0 )
It’s not pretty but hey it works!