I don't know if this applies to you or makes any difference, but are you aware of this http://www.terayon.com/tools/static_...d=100&cat_id=8
Drivers & CherryPicker upgrade. I'm not sure if that's relevant. Checking the FAQ there doesn't seem to be a web page for your modem (here) despite the profile saying the filters are user configurable.

You say LW works on & off, then there is a chance your ISP is filtering at certain times of the day. Some do this. Generally during peak periods that business would also use the service. Some isp's need to juggle their ability to cater for all. After all, their biggest income is from business.