speeds become slow after a few hours

hello, im using a dedicated server to run one of my seedbox and i seem to have a major problem i cannot mange to solve.
i have 12 great .torrents loaded, now when i force them to seed they sync with the tracker and get loads of peers but after a few hours when i return to check the speeds all i see is 15kbps and lower... probably losing connection with the tracker.

now i know it aint a problem with the tracker, since im using the same tracker to seed from another seedbox @ ovh! and im maxing it out there!

i know there used to be problems with uTorrent 1.8 with trackers disconnections but ive downgraded to 1.77 and im still getting the same...
help?

Thanks in advance!