I think I used a 18F4550 for this project. if you haven't already, I would suggest you first make simple HID project to see if you can get your PC to recognize your device. If you send me your e-mail address I will send you the whole project in a zip file.

Here is the .LST file for the project, you can see the fuse setting I used.

Code:
MPASM  5.43                      USB_MIDI.ASM   2-3-2012  20:25:46         PAGE  1


LOC  OBJECT CODE     LINE SOURCE TEXT
  VALUE

                      00001 
                      00002 ; PICBASIC PRO(TM) Compiler 3.0.4.4, (c) 1998, 2011 microEngineering Labs, Inc. All Rights Reserved. 
  00000001            00003 MPASMWIN_USED                   EQU     1
                      00004 
                      00005 #define PBP_PATH        C:\PBP3\
                      00006 
                      00007 
                      00008 
                      00009 
                      00016         LIST
                      00017         LIST p = 18F4550, r = dec, w = -311, w = -230, f = inhx32
                      00018         INCLUDE "P18F4550.INC"  ; MPASM  Header
                      00001         LIST
                      00002 
                      00003 ;==========================================================================
                      00004 ;  MPASM PIC18F4550 processor include
                      00005 ; 
                      00006 ;  (c) Copyright 1999-2011 Microchip Technology, All rights reserved
                      00007 ;==========================================================================
                      00008 
                      01764         LIST
                      00021         LIST
  00F00000            00022 EEPROM_START    EQU     0F00000h
  00000020            00023 BLOCK_SIZE      EQU     32
                      00024 
                      00025 
                      00026 PBP_HARDWAREDEF  macro
                      00027   endm
                      00028 
                      00029 
                      00030         __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
300000 3EE4           00031         __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
                      00032         __CONFIG    _CONFIG2L, _PWRT_OFF_2L & _BOR_ON_2L & _BORV_3_2L & _VREGEN_ON_2L
300002 F3FF           00033         __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
300004 F9FF           00034         __CONFIG    _CONFIG3H, _CCP2MX_ON_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
300006 FF9B           00035         __CONFIG    _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & _XINST_OFF_4L
                      00036 
                      00037 
                      00038 
                      00039 ; Define statements.
                      00040 ; C:\PBP3\USB18\USB_MIDI\PICBASICPRO\USB_MIDI.PBP       00007   DEFINE WRITE_INT 1
                      00041 #define         WRITE_INT                1
                      00042 ; C:\PBP3\USB18\USB_MIDI\PICBASICPRO\USB_MIDI.PBP       00008   Define  LOADER_USED     1
                      00043 #define         LOADER_USED                     1
                      00044 ; C:\PBP3\USB18\USB_MIDI\PICBASICPRO\USB_MIDI.PBP       00009   DEFINE RESET_ORG 800h ' For Microchip US
                            B Bootloader
                      00045 #define         RESET_ORG                800h 
                      00046 ; C:\PBP3\USB18\USB_MIDI\PICBASICPRO\USB_MIDI.PBP       00010   DEFINE INTERRUPT_ORG 808h ' For Microchi
                            p USB Bootloader
                      00047 #define         INTERRUPT_ORG            808h 
                      00048 ; C:\PBP3\USB18\USB_MIDI\PICBASICPRO\USB_MIDI.PBP       00012   DEFINE OSC 48                   ' tell p
                            rogram we are using a 20mhz oscillator
                      00049 #define         OSC              48                   
MPASM  5.43                      USB_MIDI.ASM   2-3-2012  20:25:46         PAGE  2