Different sync rate each time....

[#1]

....I turn the PC on.  I leave the router on 24hrs but whenever I turn the PC on it seems as if the router has re-synced itself either when I'm in bed asleep or out at work.  For instance, over the past 3 days or so it's synced at 12.3Mbps, then 12Mbps and then back up to 12.3Mbps.  Now I get in from work and it's at 11.8Mbps.
As you can imagine, this is playing holy hell with my download speeds because, if a sync lasts for a while the throughput speeds goes up, but no sooner than it does it the synch speed changes which means the bloody download speed drops significantly.
As you can see, thanks to the router changing it's sync speed the download speed is up and down more than a cheap whore's drawers.

Date 	Download Speed 	Upload Speed 	
Today 16:47 	8815 kbps (1.1MB/s) 	371 kbps (46.4kB/s) 	Share
Today 01:49 	6723 kbps (840kB/s) 	382 kbps (47.8kB/s) 	Share
Yesterday 04:15 	10776 kbps (1.35MB/s) 	343 kbps (42.9kB/s) 	Share
Tuesday 18:40 	6699 kbps (837kB/s) 	376 kbps (47kB/s) 	Share
Tuesday 05:12 	10503 kbps (1.31MB/s) 	233 kbps (29.1kB/s) 	Share
Monday 16:36 	10506 kbps (1.31MB/s) 	231 kbps (28.9kB/s) 	Share
May 20, 15:51 	6721 kbps (840kB/s) 	386 kbps (48.3kB/s)

So, does anyone have an idea why the router mysteriously re-syncs itself?

[#2]

Hi Azagoth,
Not sure why it could be dropping. Have a look at our troubleshooting guide for some checks.
Jojo

[#3]

The router is working fine and it's plugged into the main socket.  Although it may take some time to test the microfilters, as the time in-between the automatic re-syncs can be anything from a day to a week.

[#4]

Hi Azagoth,
I can only imagine that the slight sync changes are due to slight increases in the SNR. Although the target may remain the same, a shift of 1-2dB can mean a change of 2-300k in sync.
Jojo