Right a (fairly) quick call to CS to swap the broadband config file to the pace box downstairs (I used to use the box downstairs for internet, so I already have the cabling installed to upstairs) and heres the results....
Only a few packets dropped on each PC, resulting in 0% or 1% packet loss on the PCs. Note the almost constant download rate through azureus of over 100KB/s - I don't think I've had anywhere near that speed through azureus using the samsung box (using the same torrent yesterday on the samsung earlier today i was lucky to get 50KB/s)

.
I know its not the cabling to the STB upstairs, as this problem has only appeared since the samsung was installed. Should I ask for another samsung, or can I get a SACM ?
Oh, and I spoke to Tech support last night (after 8pm so I couldnt get CS to swap the broadband round), who warned me that if the pace box gets the 1.5meg upgrade, "the box will literally blow up, I'm not kidding" I could hardly contain my laugh
Cheers,
Kneebs