Weird interaction between Vodacom mobile proxy and Reddit is Fun

I don't know if anybody else is using Reddit is Fun (RIF) for their Android-based Reddit browsing needs, but I noticed some odd behaviour and wondered if anyone could shed some light on it.

When the proxy (196.6.128.12) is enabled in the Vodacom APN, RIF is unable to load any data from Reddit (eg. articles and comments) over the mobile connection. Disable the proxy, or use wifi instead, and it works just fine. Access http://api.reddit.com from the device browser and again, it loads just fine.

I did a packet capture on the connection and noticed the following:

When using a browser, the request gets sent to the proxy, and it returns HTTP 200 (OK) and sends the contents of the page.

When using RIF, the proxy returns 302 (FOUND) and redirects to http://settings.vodacommi.co.za:8010...pi.reddit.com/. Needless to say, that's where it all falls down.

Like I said, disabling the proxy seems to solve this particular problem, so this post is mostly about sating my curiosity. Is anyone with more experience with Vodacom proxies able to explain this behaviour? Is it looking at the user-agent string to decide what to do with a connection?

Thanks