One way to achieve a higher sync in to set the Target SNRM offset (in DSLStats >>Configuration>>Advanced>>Advanced Tweaks) or send a xdslcmd configure --snr xx (I use xx=80 to sync at about 5 dB SNRM)
Rain also raises my SNR marginally.
EDIT: Just re-read...your on a slow VDSL connection, the above will not work then.
Ian