Yes, it does not matters if I comment USB_ASM_Service.pbp or not. The demo does work perfectly with USBINIT and USBService, but as soon as I comment these I loose USB enumeration.

I also wish to use USB_ASM_Service.pbp in conjunction with Darrel's SPWM_INT.bas which does not seems possible right now (it gives an INTHAND symbol cannot be refefined error, which is normal because it appears twice). I could do the USBService interrupt with the SPWM interrupt at the same time... I do not have tight frequency requirements for the PWM signal (about 100Hz or more), what I'm interested in is the duty cycle. The main idea of my project is based on controlling the brightness of 3 LEDs by sending serial commands through USB CDC. I have to use the 13K50 for this application, but there's only one ECCP module.

But first things first, making USB_ASM_Service.pbp work with the demo! Hopefully Darrel can spare a little time to check what is going wrong here.