Is it in an FTTC enabled area?
Maybe more and more ADSL customers moving over to FTTC is reducing cross-talk from the ADSL lines which still go all the way back to the exchange?
Your Mum has certainly gained a few extra frequencies AND the signal strength of the lower ones has increased, too.
EDIT: There is one very noticeable difference - see the closed gap between upstream & downstream frequencies?
vDSL2 FTTC Infinity with BT
DL Sync 80Mbps
UL Sync 20Mbps
Edited by adebov (Sun 13-Jan-13 22:28:45)