Colo server not connecting via cURL

I am an artist with enough php to be dangerous who is fighting a colo server
that was making a cURL connection and suddenly will not. No one changed anything
on the server or the script during the time it began to fail.

The server runs Linux and under my root control (someone configured it for me).
The cURL information on the phpinfo page is libcurl/7.12.1 OpenSSL/0.9.7f
zlib/1.2.2.2 libidn/0.5.15.

The original script was to connect to the authorize.net gateway in ssl.

I've conducted numerous test cURL connections with the following results:

>From SSL to SSL, from Public to Public it works everywhere BUT the colo.