Where is the voltage variation?
I suspect your problem is in the values you load into CCPR1L1 and CCPR2L. The frequency you are askig for is not possible with this PIC, in fact the lowest frequency PWM it can generate is 1.22KHZ, more than 10 times higher than your software suggests. I would guess the flashing LEDs is due to the software delays you added in the loop before loading the CCPR registers. In PWM mode the hardware generates the output, you can adjust it but you shouldn't have to keep reloading it.
Brian.