xrandr --newmode "1440x900_60.00"  106.50  1440 1528 1672 1904  900 903 909 934 -hsync +vsync

xrandr --addmode DVI-I-1 "1440x900_60.00"

X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  18 (RRAddOutputMode)
  Serial number of failed request:  47
  Current serial number in output stream:  48