Pan not recalling preset position accurately

Moving on with one other small issue.
Have a DL-2 unit not recalling it's pan position accurately. it's not off by much and actually seems to about the same amount everytime.
Cleaned the encoders with a little isopropal alcohol without any change.
Any input or instruction to point us in the right direction in regards to documentation for a fix/adjustment would be appreciated. Checked control and our input DMX values are accurate.
Thanks Again!!!