w540 win8.1 won't keep 60Hz refresh rate after reboot (drops to 50Hz)

[StuHaight]

Hi All.

W540, i7 ("MQ" quad), 3k IPS display, 4DIMM config 2x4GB + 2x8GB Ram, Quadro K2100m, 500GB HDD.

Windows 8.1 (not Pro). I run the 3k display in 1600x900 for already known reasons with anyone using high DPI displays. Looks fine except...

I have to consistently change the refresh rate from 50Hz to 60Hz manually after rebooting.

Rebooting reverts back to 50Hz. Changing Power Modes, Sleep, and Logging On/Off maintains the 60Hz refresh rate (given I switch it to 60Hz after booting)

I work with NTSC video so naturally I really need the 60Hz when viewing 59.970p or 60p footage.