You guys must remember something, if your other protocols such as HTTP and p2p work perfectly then it cannot be your setup (as a way of ruling it out) but rather it can be your service provider.
In terms of Afrihost, there is dynamic shaping that occurs that will give you unshaped bandwidth when the network is quiet but will shape alot more at busy times. They now have this info on shaping in the control panel i believe.
I would also spend time contacting the reps on here who will do things to better troubleshoot if it is indeed an issue on their side. It just requires some time and patience.
We haven't seen this but what if providers did custom profiles on users with a single adsl data account. Gamer A and SeriesKing B get their accounts shaped according to what they do (sort of like the QoS from Mike above)

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These networks are tweaked alot of the time and sometimes it breaks and alot of people don't come out and tell them so they suffer but the provider still gets your money.
If on Afrihost, get into contact with AfriMan and let him troubleshoot for you.
@shreez, the netflix 3D page says
link here The link above shows 3D needs 12Mb/s which they failed to show that you don't need at minimum a 12Mb/s connection
Correct me if i am wrong but you should be seeing 3D since 12Mb/s is not the minimum ;-)
Edit: the devices that will work (sadly PC support only works on their Windows 8 app but others on Win8 need to confirm :/)