Bachmann EMD DD40AX

[tomgschilling]

This loco seems to be very reluctant to move.  I've tried several different settings for CV2 and it still takes up to speed step 6 or 7 for any significant movement to take place (28 speed steps) regardless of the setting in CV2.  The highest I've tried is 48. 

Would a different decoder make a difference or is there a CV setting that I'm missing.  Any advice would be appreciated.                   ...Tom