Receive libcurl when submitting support ticket

Hi,

I have the WHMCS WP integration plugin working nicely (http://digitalessence.net/client-area/) but when I came to submit a support ticket through this I got the following error:

WHMCS Integration: 400—Bad Request
WHMCS Integration: Protocol whmcs not supported or disabled in libcurl

I've just run a test order through the system and that worked fine so it seems to at least be limited to support tickets.

Thanks.