What kind of usage issues?
i have not notice any problems with modem mode and the draytek 2850n but if i go to local server for gamershell.com i download with very poor speeds (try the connection download rate) and is flawing from 3-5 MB ...when should be 12MB
even with this not bad monitor today 03/12 is showing me lot jitter at modem mode (tested 12:15pm)
