Transmission

results were clear but it may be the non-standard port that i have open through my router? i.e. not 6881.

I am having the same issue - i believe it may be isp throttling of bit torrent traffic for me.
I was having exactly the same problem, now i'm facing it intermittently with drop out every couple of minutes. not less than 8 hours ago it worked flawlessly. I am doing google test on ISP throttling at ...