I am not at a place to test this to see if it makes a difference or not...

I (for no good reason) have this after all DEFINES and Variable declarations.
Code:
Include	"cdc_desc.bas"	' Include the CDC descriptors
INCLUDE "USB_ASM_Service.pbp"  ' USB Init and Service interrupt routines
Which is where your first USBInt is...

And maybe for the other ISR.
From USB_ASM_SERVICE.pbp
To use other high priority interrupts you can add the define *
'* DEFINE INT_HOOK handlers *
'* handlers will be called on each high priority interrupt *
'* The handlers must be ASM Interrupt compatible