2471201 it will give you slightly better speed and is also good for poor lines
if is better adsl2 (992.3) for your line use that, is because it use lower frequency tones and seems does the job better
I think your issue is dslam compatibility
I bet you must be with conexant dslam
via telnet type show adsl or adsl show and see the dslam vendor at the end of the status

You can also try an other adsl filter