1. Are you using MicroFilter (spliter) for ALL the house telephones?
2. If yes, maybe 1 of your filter is faulty. Try to plug out all the filters and telephones in your house, plug your modem directly to the wall socket and try and see the connection.
3. If intermittent DC problem still happen, try to change the telephone cable. Still cannot, try another wall socket.
4. Still cannot, borrow modem from ur fren.
5. If u tried all these and problem still happen, call stramyX to help you to do a line check.

StreamyX helpdesk agents are all useless.

My internet pakage 1M (RM88 per month) ADSL speed always 3xx.xx kbps only.
Called StreamyX helpdesk they say no problem. Streamy sucks!

By the way your speed is more than 70% of 512kbps, consider within spec already.

Maybe is the microfilter problem. You unplug all the filter and telephone in your house, plug your modem directly to the wall socket, and try to connect and see. If no problem after that, change your filter.