Drop in speed and disconnections

[#1]

Over the past few weeks I have had drops in speed and disconnections from services such as Xbox Live and Netflix, these seem to be the only things currently affected everything else seems to run fine.
This is the current speed from speedtest.net

and BT speedtest reads
1. Best Effort Test:
Download Speed : 14.24 Mbps
2. Upstream Test:
Upload Speed : 6.98 Mbps
We have had speed drops before a few months ago however we did have an engineer out and found nothing wrong with the line or hardware at this end, could you please just poke my profile and wake it up  a bit

[#2]

Hi there,
I've just been looking into this for you and the line appears to be quite stable so I'm wondering when and how you've noticed these disconnections?
<img src="http://ccgi.psmith12.plus.com/visradius/generated/image13541020366572.png"/><div style="clear:both;"></div>
The speeds are definitely a lot lower than what I can see you've had in the past so the best thing I could advise you to do at the moment is raise a fault http://faults.plus.net
Adam

[#3]

Netflix only seems to be a resent issue and it's only disconnected from the service a handful of times at no set point, however Xbox Live it is disconnecting after 5pm and mostly during multiplayer sessions of Halo 4 it's a complete disconnect from Xbox Live as a re-login to the service is required, however it has been known to disconnect completely from other games as well. We have checked with other friends within the area and no other person besides this house seems to be disconnected at the same time, and it is not the Xbox as at other times the service is fine - it only seems to happen at that time and most often during Halo 4.

[#4]

That sounds like wireless issues, not connection issues. If it is wireless devices that are seeing disconnections have you tried using a different channel?

[#5]

I thought it may be wireless issues however our other consoles, handhelds and wireless devices (including my own PC) are not affected during the disconnections of Xbox Live, it's highly frustrating  when it's not a wide spread issue I can't narrow down the issue any further, I'd love to say it's the console itself but that is completely find in other situations
I have a wifi scanner on my system and no other device occupies the channel our router is on

[#6]

Well if the Xbox is under the TV or next to a lot of other electronic devices there might be interference to the wireless adapter (where the others are clear of large metal items etc)... is there any way that you could test the connection with a network cable between the Xbox and the router to see if that makes any difference?