Singtel iPhone unable to connect to Twitter

Approximately 80% of the time, my Singtel iPhone is unable to connect to twitter.com or refresh my tweets view in Twitterific (which uses the Twitter API). This only happens when connected to the internet via 3G or GPRS. If I connect via my own WiFi network, Twitter works whenever the whale isn’t flying.

Either something is wrong with the DNS resolution over on their end, they’re blocking twitter (which makes no sense to me; it’s not the highest traffic application), or something much worse. Whatever it is, I am getting seriously pissed off.