Bc2000 (for the BCF2000 & BCR2000)

i have had the bcr2000 for a couple of months now and recently encoders 2 and 7 seem to take several turns to get to the maximum. 

from what i have read this is not an error with the the bcr itself, but how it's set up or programmed. 

i have looked at the settings of the other encoders and tried to adjust accordingly but this changes nothing.

has anybody else had the same problem or can any of you offer any advice please.