Consider this section of your code:

Code:
'create a  +/- value centered at 512
    left1 = abs(analogleft-512)
    right1 = abs(analogright-512)
    
    'scale value and create centered deadband of +/-10
    'value should fall between -10 and 256 for duty cycle
    
    dutycycleleft = ((left1 * 52)/100)-10
    dutycycleright =  ((right1 *52)/100)-10
PBP only supports unsigned integers, meaning negative numbers are not supported. There can be no "-10"

For example, you have a word variable "dutycycleleft". As a word, it can hold a value from 0 to 65555. If the current value is 5 and you subtract 10 then the variable will underflow by 5 and become 65531 instead of -5. This will cause the PWM to go full on.

A quick and dirty way to fix the code is to take this from your code:
Code:
if dutycycleleft < 1 then       'if dutycycle is between -10 and 1
       dutycycleleft = 0         'then it equals zero
    endif
And change it to:
Code:
  if dutycycle left > 300 then
      dutycycleleft = 0
  endif

Do the same for dutycycleright

Try this and let me know how it works out