workaround when you are behind a proxy

Proxy_SagePaySuite

I have added this patch which should fix it 
Payment.php
Add at line 1939
if($this->getConfigData('proxy_enabled')) {
$proxy_user_pwd = $this->getConfigData('proxy_user').':'.$this->getConfigData('proxy_pass');
$proxy_host_port = 'http://'.$this->getConfigData('proxy_host').':'.$this->getConfigData('proxy_port');
curl_setopt($curlSession, CURLOPT_PROXYUSERPWD, $usrPwd);
curl_setopt($curlSession, CURLOPT_PROXY, $proxy_host_port);
}

The you just need to add config fields to the admin for
* proxy_enabled - (Yes/No select)
* proxy_user - (Text)
* proxy_pass- (Text)
* proxy_host- (Text)
* proxy_port- (Text)

Hope this helps. I have not been able to test every payment method but it seemed to work ok for me.