sky anytime+ being speed capped?

[#1]

As I noticed sky anytime+ being opened to customers not on sky broadband, I thought
i'd download a film from their movie store tonight.
It started downloading ar between 2 and 3 mbps, but soon dropped to 400kbps which is too slow to download and watch at the same time.
I restarted the sky box and reset my adsl connection and tried again.  Same result.
Is sky anytime+ being throttled by plusnet at certain times, and if so, why?  I've paid for the extra plusnet option that moves most things into the gold or platinum categories, so I'd hope that anytime+ would go unrestricted.
Anybody else seeing similar patterns?
Thanks.
-- gyre --

[#2]

If you are on Extra - without the Pro addon - then download sites are quite heavily restricted.
I would assume that Sky anytime+ is classed as a download site not as streaming.
You could try a Wireshark to check http://community.plus.net/library/faults/using-wireshark-for-data-capture/
If you have the Pro option I have no idea but it might be the Sky servers

[#3]

I'm on extra + pro.
Gonna be hard to wireshark this traffic as I only have switches in the house and not hubs, so have no monitoring ports available.
Thanks.
-- gyre --

[#4]

As its Sky they probably didn't plan for the demand for the service and are getting hammered.

[#5]

I initially thought that too. 
However it was curious that the download rate during peak time quickly settled down to around 400kbps each time.
If they were just overloaded, surely it would be far more spikey.  Somebody, either plusnet or sky, IMHO, is doing explicit traffic shaping, I thiink.
I'll borrow a hub from work today and check out those packets.
-- gyre --