The power level has absolutely nothing to do with it.  Your power levels are well within spec.

The problem is that you are the proud owner of the worst looking Bitloading graph ever posted to the Internet.  

The nulls in your bitloading graph are caused by bridge taps. A bridge tap is an extra length of wire attached to your pair that doesn't terminate anywhere. It is usually left over from a previous customer that used your pair, or sometimes because of particular wiring schemes used in your home. Bridge taps cause problems with xDSL services.

You should call technical support, have them send a premises tech to your house to check the line. He should open a helper ticket with the Installation and Maintenance group (I&M), which are the linesmen, to come find and remove the bridge tap(s).

Also, what could also possibly help is a home run from the NID directly to your modem.  The premises technician can install this when he comes.