But all it does is slow down the code since both DJNZ Rn and JNB use the same number of cycles. Here's how I would do this:

;Demonstration only. Timer setup is your problem.
       push ACC        ;Save Accumulator
       push PSW        ;Save Program Status Word
       mov  PSW, #08   ;Select Register bank 1
       djnz r0,nxtr1   ;Decrement and test r0 for zero
       clr  P2.0       ;If it is, turn off the bit
nxtr1: djnz r1,nxtr2   ;Decrement and test r1 for zero
       clr  P2.1       ;If it is, turn off the bit
nxtr2: djnz r2,nxtr3   ;Decrement and test r2 for zero
       clr  P2.2       ;If it is, turn off the bit
nxtr3: ................

       djnz CTR, ENDi
       mov  CTR, #255  ;Reload CTR counter
       mov  r0,PWM0    ;Reload registers with PWM values
       mov  r1,PWM1
       .......
       mov  P2,#255    ;Turn all bits on again
ENDi:  pop  PSW        ;Restore Program Status Word
       pop  ACC        ;Restore Accumulator
       reti